From bf2ceaa40946a51b9e6c969e2fd9e961f56997d3 Mon Sep 17 00:00:00 2001
From: Andrew Dunstan <andrew@dunslane.net>
Date: Thu, 16 Sep 2021 10:15:53 -0400
Subject: [PATCH 4/6] SQL/JSON query functions

---
 doc/src/sgml/func.sgml                      |  516 +++++++++-
 src/backend/executor/execExpr.c             |  206 +++-
 src/backend/executor/execExprInterp.c       |  543 ++++++++++
 src/backend/jit/llvm/llvmjit_expr.c         |    6 +
 src/backend/jit/llvm/llvmjit_types.c        |    1 +
 src/backend/nodes/copyfuncs.c               |  150 +++
 src/backend/nodes/equalfuncs.c              |   82 ++
 src/backend/nodes/makefuncs.c               |   15 +
 src/backend/nodes/nodeFuncs.c               |  186 +++-
 src/backend/nodes/outfuncs.c                |   70 ++
 src/backend/nodes/readfuncs.c               |   86 ++
 src/backend/optimizer/path/costsize.c       |    3 +-
 src/backend/optimizer/util/clauses.c        |   32 +
 src/backend/parser/gram.y                   |  333 +++++-
 src/backend/parser/parse_collate.c          |    4 +
 src/backend/parser/parse_expr.c             |  490 ++++++++-
 src/backend/parser/parse_target.c           |   15 +
 src/backend/utils/adt/formatting.c          |   45 +-
 src/backend/utils/adt/jsonb.c               |   62 ++
 src/backend/utils/adt/jsonfuncs.c           |   50 +-
 src/backend/utils/adt/jsonpath.c            |  257 +++++
 src/backend/utils/adt/jsonpath_exec.c       |  350 ++++++-
 src/backend/utils/adt/ruleutils.c           |  135 +++
 src/backend/utils/misc/queryjumble.c        |   21 +
 src/include/executor/execExpr.h             |   54 +
 src/include/executor/executor.h             |    2 +
 src/include/nodes/makefuncs.h               |    1 +
 src/include/nodes/nodes.h                   |    8 +
 src/include/nodes/parsenodes.h              |   59 ++
 src/include/nodes/primnodes.h               |  109 ++
 src/include/parser/kwlist.h                 |   11 +
 src/include/utils/formatting.h              |    4 +
 src/include/utils/jsonb.h                   |    3 +
 src/include/utils/jsonfuncs.h               |    4 +
 src/include/utils/jsonpath.h                |   33 +
 src/test/regress/expected/json_sqljson.out  |   15 +
 src/test/regress/expected/jsonb_sqljson.out | 1018 +++++++++++++++++++
 src/test/regress/parallel_schedule          |    2 +-
 src/test/regress/sql/json_sqljson.sql       |   11 +
 src/test/regress/sql/jsonb_sqljson.sql      |  317 ++++++
 40 files changed, 5185 insertions(+), 124 deletions(-)
 create mode 100644 src/test/regress/expected/json_sqljson.out
 create mode 100644 src/test/regress/expected/jsonb_sqljson.out
 create mode 100644 src/test/regress/sql/json_sqljson.sql
 create mode 100644 src/test/regress/sql/jsonb_sqljson.sql

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index f7066bd928..7972b415c5 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -18286,6 +18286,21 @@ FROM films AS f;
        <link linkend="functions-isjson-predicate"><literal>IS JSON</literal></link>
       </para>
     </listitem>
+    <listitem>
+      <para>
+       <link linkend="functions-jsonexists"><literal>JSON_EXISTS</literal></link>
+      </para>
+    </listitem>
+    <listitem>
+      <para>
+       <link linkend="functions-jsonvalue"><literal>JSON_VALUE</literal></link>
+      </para>
+    </listitem>
+    <listitem>
+      <para>
+       <link linkend="functions-jsonquery"><literal>JSON_QUERY</literal></link>
+      </para>
+    </listitem>
   </itemizedlist>
 
   <para>
@@ -18315,6 +18330,501 @@ INSERT INTO my_films VALUES (
 </programlisting>
      </para>
 
+   <sect4 id="functions-jsonexists">
+    <title><literal>JSON_EXISTS</literal></title>
+    <indexterm><primary>json_exists</primary></indexterm>
+
+<synopsis>
+<function>JSON_EXISTS</function> (
+  <replaceable>context_item</replaceable>, <replaceable>path_expression</replaceable> <optional> PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } <optional>, ...</optional></optional>
+  <optional> RETURNING <replaceable class="parameter">data_type</replaceable> </optional>
+  <optional> { TRUE | FALSE | UNKNOWN | ERROR } ON ERROR </optional>
+)
+</synopsis>
+
+    <sect5>
+     <title>Description</title>
+
+     <para>
+      <function>JSON_EXISTS</function> function checks whether the provided
+      <acronym>JSON</acronym> path expression can return any <acronym>SQL/JSON</acronym> items.
+     </para>
+    </sect5>
+
+    <sect5>
+     <title>Parameters</title>
+  <variablelist>
+   <varlistentry>
+    <term>
+     <literal><replaceable>context_item</replaceable>, <replaceable>path_expression</replaceable> <optional> PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } <optional>, ...</optional></optional></literal>
+    </term>
+    <listitem>
+
+    <para>
+     The input data to query, the JSON path expression defining the query, and an optional <literal>PASSING</literal> clause.
+     See <xref linkend="sqljson-input-clause"/> for details.
+    </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term>
+     <literal>RETURNING <replaceable class="parameter">data_type</replaceable></literal>
+    </term>
+    <listitem>
+     <para>
+       The output clause that specifies the data type of the returned value.
+       The specified data type should have a cast from a <literal>boolean</literal>
+       type, which is returned by default.
+     </para>
+     </listitem>
+   </varlistentry>
+
+  <varlistentry>
+    <term>
+     <literal>{ TRUE | FALSE | UNKNOWN | ERROR } ON ERROR</literal>
+    </term>
+    <listitem>
+     <para>
+       Defines the return value if an error occurs. The default value is <literal>FALSE</literal>.
+     </para>
+     </listitem>
+   </varlistentry>
+
+   </variablelist>
+    </sect5>
+
+    <sect5>
+     <title>Examples</title>
+
+  <para>
+    Check whether the provided <type>jsonb</type> data contains a
+    key/value pair with the <literal>key1</literal> key, and its value
+    contains an array with one or more elements bigger than 2:
+  </para>
+<screen>
+SELECT JSON_EXISTS(jsonb '{"key1": [1,2,3]}', 'strict $.key1[*] ? (@ > 2)');
+ json_exists
+-------------
+ t
+(1 row)
+</screen>
+
+  <para>
+   Note the difference between strict and lax modes
+   if the required item does not exist:
+  </para>
+<screen>
+-- Strict mode with ERROR on ERROR clause
+SELECT JSON_EXISTS(jsonb '{"a": [1,2,3]}', 'strict $.a[5]' ERROR ON ERROR);
+ERROR: Invalid SQL/JSON subscript
+(1 row)
+</screen>
+
+<screen>
+-- Lax mode
+SELECT JSON_EXISTS(jsonb '{"a": [1,2,3]}', 'lax $.a[5]' ERROR ON ERROR);
+ json_exists
+-------------
+ f
+(1 row)
+</screen>
+
+<screen>
+-- Strict mode using the default value for the ON ERROR clause
+SELECT JSON_EXISTS(jsonb '{"a": [1,2,3]}', 'strict $.a[5]');
+ json_exists
+-------------
+ f
+(1 row)
+</screen>
+
+    </sect5>
+   </sect4>
+
+   <sect4 id="functions-jsonvalue">
+    <title><literal>JSON_VALUE</literal></title>
+    <indexterm><primary>json_value</primary></indexterm>
+
+<synopsis>
+<function>JSON_VALUE</function> (
+  <replaceable>context_item</replaceable>, <replaceable>path_expression</replaceable> <optional> PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } <optional>, ...</optional></optional>
+  <optional> RETURNING <replaceable class="parameter">data_type</replaceable> </optional>
+  <optional> { ERROR | NULL | DEFAULT <replaceable class="parameter">expression</replaceable> } ON EMPTY </optional>
+  <optional> { ERROR | NULL | DEFAULT <replaceable class="parameter">expression</replaceable> } ON ERROR </optional>
+)
+  </synopsis>
+
+    <sect5>
+     <title>Description</title>
+
+  <para>
+   <function>JSON_VALUE</function> function extracts a value from the provided
+   <acronym>JSON</acronym> data and converts it to an <acronym>SQL</acronym> scalar.
+   If the specified JSON path expression returns more than one
+   <acronym>SQL/JSON</acronym> item, an error occurs. To extract
+   an <acronym>SQL/JSON</acronym> array or object, use <xref linkend="functions-jsonquery"/>.
+  </para>
+    </sect5>
+
+    <sect5>
+     <title>Parameters</title>
+
+  <variablelist>
+
+   <varlistentry>
+    <term>
+     <literal><replaceable>context_item</replaceable>, <replaceable>path_expression</replaceable> <optional> PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } <optional>, ...</optional></optional></literal>
+    </term>
+    <listitem>
+
+    <para>
+     The input data to query, the JSON path expression defining the query, and an optional <literal>PASSING</literal> clause.
+     For details, see <xref linkend="functions-sqljson-path"/>.
+    </para>
+    </listitem>
+   </varlistentry>
+
+  <varlistentry>
+    <term>
+     <literal>RETURNING <replaceable class="parameter">data_type</replaceable></literal>
+    </term>
+    <listitem>
+     <para>
+       The output clause that specifies the data type of the returned value.
+       Out of the box, <productname>PostgreSQL</productname>
+       supports the following types: <literal>json</literal>, <literal>jsonb</literal>,
+       <literal>bytea</literal>, and character string types (<literal>text</literal>, <literal>char</literal>,
+       <literal>varchar</literal>, and <literal>nchar</literal>).
+       The extracted value must be a single <acronym>SQL/JSON</acronym> scalar item
+       and have a cast to the specified type. Otherwise, an error occurs.
+       By default, <function>JSON_VALUE</function> returns a string
+       of the <literal>text</literal> type.
+     </para>
+     </listitem>
+   </varlistentry>
+
+  <varlistentry>
+    <term>
+     <literal>{ ERROR | NULL | DEFAULT <replaceable class="parameter">expression</replaceable> } ON EMPTY</literal>
+    </term>
+    <listitem>
+     <para>
+       Defines the return value if no JSON value is found. The default is
+       <literal>NULL</literal>. If you use
+       <literal>DEFAULT <replaceable class="parameter">expression</replaceable></literal>,
+       the provided <replaceable class="parameter">expression</replaceable> is
+       evaluated and cast to the type specified in the <command>RETURNING</command> clause.
+     </para>
+     </listitem>
+   </varlistentry>
+
+     <varlistentry>
+    <term>
+     <literal>{ ERROR | NULL | DEFAULT <replaceable class="parameter">expression</replaceable> } ON ERROR</literal>
+    </term>
+    <listitem>
+     <para>
+       Defines the return value if an unhandled error occurs. The default is
+       <literal>NULL</literal>. If you use
+       <literal>DEFAULT <replaceable class="parameter">expression</replaceable></literal>,
+       the provided <replaceable class="parameter">expression</replaceable> is
+       evaluated and cast to the type specified in the <command>RETURNING</command> clause.
+     </para>
+     </listitem>
+   </varlistentry>
+
+   </variablelist>
+    </sect5>
+
+    <sect5>
+     <title>Examples</title>
+
+     <para>
+      Extract an SQL/JSON value and return it as an SQL
+      scalar of the specified type. Note that
+      <command>JSON_VALUE</command> can only return a
+      single scalar, and the returned value must have a
+      cast to the specified return type:
+     </para>
+
+<screen>
+SELECT JSON_VALUE('"123.45"', '$' RETURNING float);
+ json_value
+------------
+     123.45
+(1 row)
+
+SELECT JSON_VALUE('123.45', '$' RETURNING int ERROR ON ERROR);
+ json_value
+------------
+        123
+(1 row)
+
+SELECT JSON_VALUE('"03:04 2015-02-01"', '$.datetime("HH24:MI YYYY-MM-DD")' RETURNING date);
+ json_value 
+------------
+ 2015-02-01
+(1 row)
+
+SELECT JSON_VALUE('"123.45"', '$' RETURNING int ERROR ON ERROR);
+ERROR:  invalid input syntax for integer: "123.45"
+
+SELECT JSON_VALUE(jsonb '[1]', 'strict $' ERROR ON ERROR);
+ERROR: SQL/JSON scalar required
+
+SELECT JSON_VALUE(jsonb '[1,2]', 'strict $[*]' ERROR ON ERROR);
+ERROR: more than one SQL/JSON item
+</screen>
+
+     <para>
+       If the path expression returns an array, an object, or
+       multiple SQL/JSON items, an error is returned, as specified
+       in the <command>ON ERROR</command> clause:
+     </para>
+<screen>
+SELECT JSON_VALUE(jsonb '[1]', 'strict $' ERROR ON ERROR);
+ERROR: SQL/JSON scalar required
+
+SELECT JSON_VALUE(jsonb '{"a": 1}', 'strict $' ERROR ON ERROR);
+ERROR: SQL/JSON scalar required
+
+SELECT JSON_VALUE(jsonb '[1,2]', 'strict $[*]' ERROR ON ERROR);
+ERROR: more than one SQL/JSON item
+
+SELECT JSON_VALUE(jsonb '[1,2]', 'strict $[*]' DEFAULT 1 ON ERROR);
+1
+</screen>
+
+    </sect5>
+   </sect4>
+
+   <sect4 id="functions-jsonquery">
+    <title><literal>JSON_QUERY</literal></title>
+    <indexterm><primary>json_query</primary></indexterm>
+
+<synopsis>
+<function>JSON_QUERY</function> (
+  <replaceable>context_item</replaceable>, <replaceable>path_expression</replaceable> <optional> PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } <optional>, ...</optional></optional>
+  <optional> RETURNING <replaceable class="parameter">data_type</replaceable> <optional> FORMAT JSON <optional> ENCODING UTF8 </optional> </optional> </optional>
+  <optional> { WITHOUT | WITH { CONDITIONAL | <optional>UNCONDITIONAL</optional> } } <optional> ARRAY </optional> WRAPPER </optional>
+  <optional> { KEEP | OMIT } QUOTES <optional> ON SCALAR STRING </optional> </optional>
+  <optional> { ERROR | NULL | EMPTY { <optional> ARRAY </optional> | OBJECT } | DEFAULT <replaceable class="parameter">expression</replaceable> } ON EMPTY </optional>
+  <optional> { ERROR | NULL | EMPTY { <optional> ARRAY </optional> | OBJECT } | DEFAULT <replaceable class="parameter">expression</replaceable> } ON ERROR </optional>
+)
+  </synopsis>
+
+    <sect5>
+     <title>Description</title>
+
+  <para>
+   <function>JSON_QUERY</function> function extracts an <acronym>SQL/JSON</acronym>
+   array or object from <acronym>JSON</acronym> data. This function must return
+   a JSON string, so if the path expression returns a scalar or multiple SQL/JSON
+   items, you must wrap the result using the <literal>WITH WRAPPER</literal> clause.
+   To extract a single <acronym>SQL/JSON</acronym> value, you can use <xref linkend="functions-jsonvalue"/>.
+  </para>
+    </sect5>
+
+    <sect5>
+     <title>Parameters</title>
+
+   <variablelist>
+
+   <varlistentry>
+    <term>
+     <literal><replaceable>context_item</replaceable>, <replaceable>path_expression</replaceable> <optional> PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } <optional>, ...</optional></optional></literal>
+    </term>
+    <listitem>
+
+    <para>
+     The input data to query, the JSON path expression defining the query, and an optional <literal>PASSING</literal> clause.
+     For details, see <xref linkend="functions-sqljson-path"/>.
+    </para>
+    </listitem>
+   </varlistentry>
+
+  <varlistentry>
+    <term>
+     <literal>RETURNING <replaceable class="parameter">data_type</replaceable> <optional> FORMAT JSON <optional> ENCODING UTF8 </optional> </optional></literal>
+    </term>
+    <listitem>
+     <para>
+       The output clause that specifies the data type of the returned value.
+       For details, see <xref linkend="sqljson-output-clause"/>.
+     </para>
+     </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term>
+     <literal>{ WITHOUT | WITH { CONDITIONAL | <optional>UNCONDITIONAL</optional> } } <optional> ARRAY </optional> WRAPPER</literal>
+    </term>
+    <listitem>
+     <para>
+       Defines whether to wrap a returned sequence of <acronym>SQL/JSON</acronym>
+       items into a <acronym>SQL/JSON</acronym> array.
+     </para>
+       <variablelist>
+        <varlistentry>
+        <term><literal>WITHOUT WRAPPER</literal></term>
+        <listitem>
+          <para>
+            Do not wrap the result.
+            This is the default behavior if the <literal>WRAPPER</literal>
+            clause is omitted.
+          </para>
+        </listitem>
+        </varlistentry>
+        <varlistentry>
+        <term><literal>WITH <optional>UNCONDITIONAL</optional> WRAPPER</literal></term>
+        <listitem>
+          <para>
+            Always wrap the result.
+          </para>
+        </listitem>
+        </varlistentry>
+        <varlistentry>
+        <term><literal>WITH CONDITIONAL WRAPPER</literal></term>
+        <listitem>
+          <para>
+            Wrap the result if the path
+            expression returns anything other than a single
+            <acronym>SQL/JSON</acronym> array or object.
+          </para>
+        </listitem>
+        </varlistentry>
+       </variablelist>
+     <para>
+       Optionally, you can add the <literal>ARRAY</literal> keyword for semantic clarity.
+     </para>
+     <important>
+      <para>You cannot use this clause together with the <literal>ON EMPTY</literal> clause.
+      </para>
+     </important>
+     </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term>
+     <literal>{ KEEP | OMIT } QUOTES <optional> ON SCALAR STRING </optional></literal>
+    </term>
+    <listitem>
+     <para>
+       Defines whether to keep or omit quotes if a scalar string is returned.
+       By default, scalar strings are returned with quotes. Using this
+       clause together with the <command>WITH WRAPPER</command> clause is not allowed.
+     </para>
+     <para>
+       Optionally, you can add the <literal>ON SCALAR STRING</literal> keywords for semantic clarity.
+     </para>
+     </listitem>
+   </varlistentry>
+
+  <varlistentry>
+    <term>
+     <literal>{ ERROR | NULL | EMPTY { <optional> ARRAY </optional> | OBJECT } | DEFAULT <replaceable class="parameter">expression</replaceable> } ON EMPTY</literal>
+    </term>
+    <listitem>
+     <para>
+       Defines the return value if no JSON value is found. The default is <literal>NULL</literal>.
+       If you use <literal>EMPTY <optional>ARRAY</optional></literal> or <literal>EMPTY OBJECT</literal>,
+       an empty JSON array [] or object {} is returned, respectively.
+       If you use <literal>DEFAULT <replaceable class="parameter">expression</replaceable></literal>,
+       the provided <replaceable class="parameter">expression</replaceable> is evaluated and cast
+       to the type specified in the <command>RETURNING</command> clause.
+     </para>
+     <para>
+       You cannot use this clause together with the <literal>WRAPPER</literal> clause.
+     </para>
+     </listitem>
+   </varlistentry>
+
+     <varlistentry>
+    <term>
+     <literal>{ ERROR | NULL | EMPTY { <optional> ARRAY </optional> | OBJECT } | DEFAULT <replaceable class="parameter">expression</replaceable> } ON ERROR</literal>
+    </term>
+    <listitem>
+     <para>
+       Defines the return value if an unhandled error occurs. The default is <literal>NULL</literal>.
+       If you use <literal>EMPTY <optional>ARRAY</optional></literal> or <literal>EMPTY OBJECT</literal>,
+       an empty JSON array <literal>[]</literal> or object <literal>{}</literal> are returned, respectively.
+       If you use <literal>DEFAULT <replaceable class="parameter">expression</replaceable></literal>,
+       the provided <replaceable class="parameter">expression</replaceable> is evaluated and cast
+       to the type specified in the <command>RETURNING</command> clause.
+     </para>
+     </listitem>
+   </varlistentry>
+
+   </variablelist>
+    </sect5>
+
+    <sect5>
+     <title>Examples</title>
+
+     <para>
+      Extract all film genres listed in the <structname>my_films</structname> table:
+     </para>
+     <screen>
+SELECT
+    JSON_QUERY(js, '$.favorites[*].kind' WITH WRAPPER ERROR ON ERROR)
+FROM my_films;
+ json_query
+------------
+ ["comedy", "horror", "thriller", "drama"]
+(1 row)
+</screen>
+
+     <para>
+      Note that the same query will result in an error if you omit the
+      <command>WITH WRAPPER</command> clause, as it returns multiple SQL/JSON items:
+     </para>
+     <screen>
+SELECT
+    JSON_QUERY(js, '$.favorites[*].kind' ERROR ON ERROR)
+FROM my_films;
+ERROR: more than one SQL/JSON item 
+</screen>
+
+     <para>
+       Compare the effect of different <literal>WRAPPER</literal> clauses:
+     </para>
+     <screen>
+SELECT
+    js,
+    JSON_QUERY(js, 'lax $[*]') AS "without",
+    JSON_QUERY(js, 'lax $[*]' WITH WRAPPER)  AS "with uncond",
+    JSON_QUERY(js, 'lax $[*]' WITH CONDITIONAL WRAPPER) AS "with cond"
+FROM
+    (VALUES (jsonb '[]'), ('[1]'), ('[[1,2,3]]'),  ('[{"a": 1}]'), ('[1, null, "2"]')) foo(js);
+       js       |  without  |  with uncond   |   with cond
+----------------+-----------+----------------+----------------
+ []             | (null)    | (null)         | (null)
+ [1]            | 1         | [1]            | [1]
+ [[1, 2, 3]]    | [1, 2, 3] | [[1, 2, 3]]    | [1, 2, 3]
+ [{"a": 1}]     | {"a": 1}  | [{"a": 1}]     | {"a": 1}
+ [1, null, "2"] | (null)    | [1, null, "2"] | [1, null, "2"]
+(5 rows)
+</screen>
+
+<para>Compare quote handling for scalar types with and without the <command>OMIT QUOTES</command> clause:
+</para>
+     <screen>
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text);
+ json_query
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES);
+ json_query
+------------
+ aaa
+(1 row)
+</screen>
+    </sect5>
+   </sect4>
+
    <sect4 id="functions-isjson-predicate">
     <title><literal>IS JSON</literal></title>
     <indexterm><primary>is_json</primary></indexterm>
@@ -18474,7 +18984,7 @@ FROM
   <varlistentry>
     <term>
      <literal><replaceable>context_item</replaceable>, <replaceable>path_expression</replaceable>
-[ PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } [, ...]]</literal>
+<optional> PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } <optional>, ...</optional></optional></literal>
     </term>
     <listitem>
      <para>
@@ -18503,7 +19013,7 @@ FROM
      </listitem>
     </itemizedlist>
     <para>
-    The input clause is common for all SQL/JSON query functions.
+     The input clause is common for all SQL/JSON query functions.
     </para>
      </listitem>
    </varlistentry>
@@ -18517,7 +19027,7 @@ FROM
     <variablelist>
   <varlistentry>
     <term>
-     <literal>RETURNING <replaceable class="parameter">data_type</replaceable> [ FORMAT JSON [ ENCODING UTF8 ] ]</literal>
+     <literal>RETURNING <replaceable class="parameter">data_type</replaceable> <optional> FORMAT JSON <optional> ENCODING UTF8 </optional> </optional></literal>
     </term>
     <listitem>
      <para>
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 6e4018d831..08f3da7e80 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -47,6 +47,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/datum.h"
+#include "utils/jsonpath.h"
 #include "utils/lsyscache.h"
 #include "utils/typcache.h"
 
@@ -85,6 +86,40 @@ static void ExecBuildAggTransCall(ExprState *state, AggState *aggstate,
 								  bool nullcheck);
 
 
+static ExprState *
+ExecInitExprInternal(Expr *node, PlanState *parent, ParamListInfo ext_params,
+					 Datum *caseval, bool *casenull)
+{
+	ExprState  *state;
+	ExprEvalStep scratch = {0};
+
+	/* Special case: NULL expression produces a NULL ExprState pointer */
+	if (node == NULL)
+		return NULL;
+
+	/* Initialize ExprState with empty step list */
+	state = makeNode(ExprState);
+	state->expr = node;
+	state->parent = parent;
+	state->ext_params = ext_params;
+	state->innermost_caseval = caseval;
+	state->innermost_casenull = casenull;
+
+	/* Insert EEOP_*_FETCHSOME steps as needed */
+	ExecInitExprSlots(state, (Node *) node);
+
+	/* Compile the expression proper */
+	ExecInitExprRec(node, state, &state->resvalue, &state->resnull);
+
+	/* Finally, append a DONE step */
+	scratch.opcode = EEOP_DONE;
+	ExprEvalPushStep(state, &scratch);
+
+	ExecReadyExpr(state);
+
+	return state;
+}
+
 /*
  * ExecInitExpr: prepare an expression tree for execution
  *
@@ -122,32 +157,7 @@ static void ExecBuildAggTransCall(ExprState *state, AggState *aggstate,
 ExprState *
 ExecInitExpr(Expr *node, PlanState *parent)
 {
-	ExprState  *state;
-	ExprEvalStep scratch = {0};
-
-	/* Special case: NULL expression produces a NULL ExprState pointer */
-	if (node == NULL)
-		return NULL;
-
-	/* Initialize ExprState with empty step list */
-	state = makeNode(ExprState);
-	state->expr = node;
-	state->parent = parent;
-	state->ext_params = NULL;
-
-	/* Insert EEOP_*_FETCHSOME steps as needed */
-	ExecInitExprSlots(state, (Node *) node);
-
-	/* Compile the expression proper */
-	ExecInitExprRec(node, state, &state->resvalue, &state->resnull);
-
-	/* Finally, append a DONE step */
-	scratch.opcode = EEOP_DONE;
-	ExprEvalPushStep(state, &scratch);
-
-	ExecReadyExpr(state);
-
-	return state;
+	return ExecInitExprInternal(node, parent, NULL, NULL, NULL);
 }
 
 /*
@@ -159,32 +169,20 @@ ExecInitExpr(Expr *node, PlanState *parent)
 ExprState *
 ExecInitExprWithParams(Expr *node, ParamListInfo ext_params)
 {
-	ExprState  *state;
-	ExprEvalStep scratch = {0};
-
-	/* Special case: NULL expression produces a NULL ExprState pointer */
-	if (node == NULL)
-		return NULL;
-
-	/* Initialize ExprState with empty step list */
-	state = makeNode(ExprState);
-	state->expr = node;
-	state->parent = NULL;
-	state->ext_params = ext_params;
-
-	/* Insert EEOP_*_FETCHSOME steps as needed */
-	ExecInitExprSlots(state, (Node *) node);
-
-	/* Compile the expression proper */
-	ExecInitExprRec(node, state, &state->resvalue, &state->resnull);
-
-	/* Finally, append a DONE step */
-	scratch.opcode = EEOP_DONE;
-	ExprEvalPushStep(state, &scratch);
-
-	ExecReadyExpr(state);
+	return ExecInitExprInternal(node, NULL, ext_params, NULL, NULL);
+}
 
-	return state;
+/*
+ * ExecInitExprWithCaseValue: prepare an expression tree for execution
+ *
+ * This is the same as ExecInitExpr, except that a pointer to the value for
+ * CasTestExpr is passed here.
+ */
+ExprState *
+ExecInitExprWithCaseValue(Expr *node, PlanState *parent,
+						  Datum *caseval, bool *casenull)
+{
+	return ExecInitExprInternal(node, parent, NULL, caseval, casenull);
 }
 
 /*
@@ -2526,6 +2524,112 @@ ExecInitExprRec(Expr *node, ExprState *state,
 				break;
 			}
 
+		case T_JsonExpr:
+			{
+				JsonExpr   *jexpr = castNode(JsonExpr, node);
+				ListCell   *argexprlc;
+				ListCell   *argnamelc;
+
+				scratch.opcode = EEOP_JSONEXPR;
+				scratch.d.jsonexpr.jsexpr = jexpr;
+
+				scratch.d.jsonexpr.formatted_expr =
+					palloc(sizeof(*scratch.d.jsonexpr.formatted_expr));
+
+				ExecInitExprRec((Expr *) jexpr->formatted_expr, state,
+								&scratch.d.jsonexpr.formatted_expr->value,
+								&scratch.d.jsonexpr.formatted_expr->isnull);
+
+				scratch.d.jsonexpr.pathspec =
+					palloc(sizeof(*scratch.d.jsonexpr.pathspec));
+
+				ExecInitExprRec((Expr *) jexpr->path_spec, state,
+								&scratch.d.jsonexpr.pathspec->value,
+								&scratch.d.jsonexpr.pathspec->isnull);
+
+				scratch.d.jsonexpr.res_expr =
+					palloc(sizeof(*scratch.d.jsonexpr.res_expr));
+
+				scratch.d.jsonexpr.result_expr = jexpr->result_coercion
+					? ExecInitExprWithCaseValue((Expr *) jexpr->result_coercion->expr,
+												state->parent,
+												&scratch.d.jsonexpr.res_expr->value,
+												&scratch.d.jsonexpr.res_expr->isnull)
+					: NULL;
+
+				scratch.d.jsonexpr.default_on_empty = !jexpr->on_empty ? NULL :
+					ExecInitExpr((Expr *) jexpr->on_empty->default_expr,
+								 state->parent);
+
+				scratch.d.jsonexpr.default_on_error =
+					ExecInitExpr((Expr *) jexpr->on_error->default_expr,
+								 state->parent);
+
+				if (jexpr->omit_quotes ||
+					(jexpr->result_coercion && jexpr->result_coercion->via_io))
+				{
+					Oid			typinput;
+
+					/* lookup the result type's input function */
+					getTypeInputInfo(jexpr->returning->typid, &typinput,
+									 &scratch.d.jsonexpr.input.typioparam);
+					fmgr_info(typinput, &scratch.d.jsonexpr.input.func);
+				}
+
+				scratch.d.jsonexpr.args = NIL;
+
+				forboth(argexprlc, jexpr->passing_values,
+						argnamelc, jexpr->passing_names)
+				{
+					Expr	   *argexpr = (Expr *) lfirst(argexprlc);
+					String	   *argname = lfirst_node(String, argnamelc);
+					JsonPathVariableEvalContext *var = palloc(sizeof(*var));
+
+					var->name = pstrdup(argname->val);
+					var->typid = exprType((Node *) argexpr);
+					var->typmod = exprTypmod((Node *) argexpr);
+					var->estate = ExecInitExpr(argexpr, state->parent);
+					var->econtext = NULL;
+					var->evaluated = false;
+					var->value = (Datum) 0;
+					var->isnull = true;
+
+					scratch.d.jsonexpr.args =
+						lappend(scratch.d.jsonexpr.args, var);
+				}
+
+				scratch.d.jsonexpr.cache = NULL;
+
+				if (jexpr->coercions)
+				{
+					JsonCoercion **coercion;
+					struct JsonCoercionState *cstate;
+					Datum	   *caseval;
+					bool	   *casenull;
+
+					scratch.d.jsonexpr.coercion_expr =
+						palloc(sizeof(*scratch.d.jsonexpr.coercion_expr));
+
+					caseval = &scratch.d.jsonexpr.coercion_expr->value;
+					casenull = &scratch.d.jsonexpr.coercion_expr->isnull;
+
+					for (cstate = &scratch.d.jsonexpr.coercions.null,
+						 coercion = &jexpr->coercions->null;
+						 coercion <= &jexpr->coercions->composite;
+						 coercion++, cstate++)
+					{
+						cstate->coercion = *coercion;
+						cstate->estate = *coercion ?
+							ExecInitExprWithCaseValue((Expr *)(*coercion)->expr,
+													  state->parent,
+													  caseval, casenull) : NULL;
+					}
+				}
+
+				ExprEvalPushStep(state, &scratch);
+				break;
+			}
+
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 5dca4e059a..26a056b725 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -57,14 +57,18 @@
 #include "postgres.h"
 
 #include "access/heaptoast.h"
+#include "access/xact.h"
+#include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "commands/sequence.h"
 #include "executor/execExpr.h"
 #include "executor/nodeSubplan.h"
 #include "funcapi.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "parser/parsetree.h"
+#include "parser/parse_expr.h"
 #include "pgstat.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
@@ -74,8 +78,10 @@
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
+#include "utils/jsonpath.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
+#include "utils/resowner.h"
 #include "utils/timestamp.h"
 #include "utils/typcache.h"
 #include "utils/xml.h"
@@ -482,6 +488,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		&&CASE_EEOP_SUBPLAN,
 		&&CASE_EEOP_JSON_CONSTRUCTOR,
 		&&CASE_EEOP_IS_JSON,
+		&&CASE_EEOP_JSONEXPR,
 		&&CASE_EEOP_AGG_STRICT_DESERIALIZE,
 		&&CASE_EEOP_AGG_DESERIALIZE,
 		&&CASE_EEOP_AGG_STRICT_INPUT_CHECK_ARGS,
@@ -1805,7 +1812,13 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		{
 			/* too complex for an inline implementation */
 			ExecEvalJsonIsPredicate(state, op);
+			EEO_NEXT();
+		}
 
+		EEO_CASE(EEOP_JSONEXPR)
+		{
+			/* too complex for an inline implementation */
+			ExecEvalJson(state, op, econtext);
 			EEO_NEXT();
 		}
 
@@ -4529,3 +4542,533 @@ ExecEvalJsonConstructor(ExprState *state, ExprEvalStep *op,
 	*op->resvalue = res;
 	*op->resnull = isnull;
 }
+
+/*
+ * Evaluate a JSON error/empty behavior result.
+ */
+static Datum
+ExecEvalJsonBehavior(ExprContext *econtext, JsonBehavior *behavior,
+					 ExprState *default_estate, bool *is_null)
+{
+	*is_null = false;
+
+	switch (behavior->btype)
+	{
+		case JSON_BEHAVIOR_EMPTY_ARRAY:
+			return JsonbPGetDatum(JsonbMakeEmptyArray());
+
+		case JSON_BEHAVIOR_EMPTY_OBJECT:
+			return JsonbPGetDatum(JsonbMakeEmptyObject());
+
+		case JSON_BEHAVIOR_TRUE:
+			return BoolGetDatum(true);
+
+		case JSON_BEHAVIOR_FALSE:
+			return BoolGetDatum(false);
+
+		case JSON_BEHAVIOR_NULL:
+		case JSON_BEHAVIOR_UNKNOWN:
+			*is_null = true;
+			return (Datum) 0;
+
+		case JSON_BEHAVIOR_DEFAULT:
+			return ExecEvalExpr(default_estate, econtext, is_null);
+
+		default:
+			elog(ERROR, "unrecognized SQL/JSON behavior %d", behavior->btype);
+			return (Datum) 0;
+	}
+}
+
+/*
+ * Evaluate a coercion of a JSON item to the target type.
+ */
+static Datum
+ExecEvalJsonExprCoercion(ExprEvalStep *op, ExprContext *econtext,
+						 Datum res, bool *isNull, void *p, bool *error)
+{
+	ExprState *estate = p;
+
+	if (estate)		/* coerce using specified expression */
+		return ExecEvalExpr(estate, econtext, isNull);
+
+	if (op->d.jsonexpr.jsexpr->op != IS_JSON_EXISTS)
+	{
+		JsonCoercion *coercion = op->d.jsonexpr.jsexpr->result_coercion;
+		JsonExpr   *jexpr = op->d.jsonexpr.jsexpr;
+		Jsonb	   *jb = *isNull ? NULL : DatumGetJsonbP(res);
+
+		if ((coercion && coercion->via_io) ||
+			(jexpr->omit_quotes && !*isNull &&
+			 JB_ROOT_IS_SCALAR(jb)))
+		{
+			/* strip quotes and call typinput function */
+			char	   *str = *isNull ? NULL : JsonbUnquote(jb);
+
+			return InputFunctionCall(&op->d.jsonexpr.input.func, str,
+									 op->d.jsonexpr.input.typioparam,
+									 jexpr->returning->typmod);
+		}
+		else if (coercion && coercion->via_populate)
+			return json_populate_type(res, JSONBOID,
+									  jexpr->returning->typid,
+									  jexpr->returning->typmod,
+									  &op->d.jsonexpr.cache,
+									  econtext->ecxt_per_query_memory,
+									  isNull);
+	}
+
+	if (op->d.jsonexpr.result_expr)
+	{
+		op->d.jsonexpr.res_expr->value = res;
+		op->d.jsonexpr.res_expr->isnull = *isNull;
+
+		res = ExecEvalExpr(op->d.jsonexpr.result_expr, econtext, isNull);
+	}
+
+	return res;
+}
+
+/*
+ * Evaluate a JSON path variable caching computed value.
+ */
+int
+EvalJsonPathVar(void *cxt, char *varName, int varNameLen,
+				JsonbValue *val, JsonbValue *baseObject)
+{
+	JsonPathVariableEvalContext *var = NULL;
+	List	   *vars = cxt;
+	ListCell   *lc;
+	int			id = 1;
+
+	if (!varName)
+		return list_length(vars);
+
+	foreach(lc, vars)
+	{
+		var = lfirst(lc);
+
+		if (!strncmp(var->name, varName, varNameLen))
+			break;
+
+		var = NULL;
+		id++;
+	}
+
+	if (!var)
+		return -1;
+
+	if (!var->evaluated)
+	{
+		var->value = ExecEvalExpr(var->estate, var->econtext, &var->isnull);
+		var->evaluated = true;
+	}
+
+	if (var->isnull)
+	{
+		val->type = jbvNull;
+		return 0;
+	}
+
+	JsonItemFromDatum(var->value, var->typid, var->typmod, val);
+
+	*baseObject = *val;
+	return id;
+}
+
+/*
+ * Prepare SQL/JSON item coercion to the output type. Returned a datum of the
+ * corresponding SQL type and a pointer to the coercion state.
+ */
+Datum
+ExecPrepareJsonItemCoercion(JsonbValue *item,
+							JsonReturning *returning,
+							struct JsonCoercionsState *coercions,
+							struct JsonCoercionState **pcoercion)
+{
+	struct JsonCoercionState *coercion;
+	Datum		res;
+	JsonbValue	buf;
+
+	if (item->type == jbvBinary &&
+		JsonContainerIsScalar(item->val.binary.data))
+	{
+		bool		res PG_USED_FOR_ASSERTS_ONLY;
+
+		res = JsonbExtractScalar(item->val.binary.data, &buf);
+		item = &buf;
+		Assert(res);
+	}
+
+	/* get coercion state reference and datum of the corresponding SQL type */
+	switch (item->type)
+	{
+		case jbvNull:
+			coercion = &coercions->null;
+			res = (Datum) 0;
+			break;
+
+		case jbvString:
+			coercion = &coercions->string;
+			res = PointerGetDatum(
+				cstring_to_text_with_len(item->val.string.val,
+										 item->val.string.len));
+			break;
+
+		case jbvNumeric:
+			coercion = &coercions->numeric;
+			res = NumericGetDatum(item->val.numeric);
+			break;
+
+		case jbvBool:
+			coercion = &coercions->boolean;
+			res = BoolGetDatum(item->val.boolean);
+			break;
+
+		case jbvDatetime:
+			res = item->val.datetime.value;
+			switch (item->val.datetime.typid)
+			{
+				case DATEOID:
+					coercion = &coercions->date;
+					break;
+				case TIMEOID:
+					coercion = &coercions->time;
+					break;
+				case TIMETZOID:
+					coercion = &coercions->timetz;
+					break;
+				case TIMESTAMPOID:
+					coercion = &coercions->timestamp;
+					break;
+				case TIMESTAMPTZOID:
+					coercion = &coercions->timestamptz;
+					break;
+				default:
+					elog(ERROR, "unexpected jsonb datetime type oid %d",
+						 item->val.datetime.typid);
+					return (Datum) 0;
+			}
+			break;
+
+		case jbvArray:
+		case jbvObject:
+		case jbvBinary:
+			coercion = &coercions->composite;
+			res = JsonbPGetDatum(JsonbValueToJsonb(item));
+			break;
+
+		default:
+			elog(ERROR, "unexpected jsonb value type %d", item->type);
+			return (Datum) 0;
+	}
+
+	*pcoercion = coercion;
+
+	return res;
+}
+
+typedef Datum (*JsonFunc)(ExprEvalStep *op, ExprContext *econtext,
+						  Datum item, bool *resnull, void *p, bool *error);
+
+static Datum
+ExecEvalJsonExprSubtrans(JsonFunc func, ExprEvalStep *op,
+						 ExprContext *econtext,
+						 Datum res, bool *resnull,
+						 void *p, bool *error, bool subtrans)
+{
+	MemoryContext oldcontext;
+	ResourceOwner oldowner;
+
+	if (!subtrans)
+		/* No need to use subtransactions. */
+		return func(op, econtext, res, resnull, p, error);
+
+	/*
+	 * We should catch exceptions of category ERRCODE_DATA_EXCEPTION
+	 * and execute the corresponding ON ERROR behavior then.
+	 */
+	oldcontext = CurrentMemoryContext;
+	oldowner = CurrentResourceOwner;
+
+	Assert(error);
+
+	BeginInternalSubTransaction(NULL);
+	/* Want to execute expressions inside function's memory context */
+	MemoryContextSwitchTo(oldcontext);
+
+	PG_TRY();
+	{
+		res = func(op, econtext, res, resnull, p, error);
+
+		/* Commit the inner transaction, return to outer xact context */
+		ReleaseCurrentSubTransaction();
+		MemoryContextSwitchTo(oldcontext);
+		CurrentResourceOwner = oldowner;
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info in oldcontext */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Abort the inner transaction */
+		RollbackAndReleaseCurrentSubTransaction();
+		MemoryContextSwitchTo(oldcontext);
+		CurrentResourceOwner = oldowner;
+
+		if (ERRCODE_TO_CATEGORY(edata->sqlerrcode) !=
+			ERRCODE_DATA_EXCEPTION)
+			ReThrowError(edata);
+
+		res = (Datum) 0;
+		*error = true;
+	}
+	PG_END_TRY();
+
+	return res;
+}
+
+
+typedef struct
+{
+	JsonPath   *path;
+	bool	   *error;
+	bool		coercionInSubtrans;
+} ExecEvalJsonExprContext;
+
+static Datum
+ExecEvalJsonExpr(ExprEvalStep *op, ExprContext *econtext,
+				 Datum item, bool *resnull, void *pcxt,
+				 bool *error)
+{
+	ExecEvalJsonExprContext *cxt = pcxt;
+	JsonPath   *path = cxt->path;
+	JsonExpr   *jexpr = op->d.jsonexpr.jsexpr;
+	ExprState  *estate = NULL;
+	bool		empty = false;
+	Datum		res = (Datum) 0;
+
+	switch (jexpr->op)
+	{
+		case IS_JSON_QUERY:
+			res = JsonPathQuery(item, path, jexpr->wrapper, &empty, error,
+								op->d.jsonexpr.args);
+			if (error && *error)
+			{
+				*resnull = true;
+				return (Datum) 0;
+			}
+			*resnull = !DatumGetPointer(res);
+			break;
+
+		case IS_JSON_VALUE:
+			{
+				struct JsonCoercionState *jcstate;
+				JsonbValue *jbv = JsonPathValue(item, path, &empty, error,
+												op->d.jsonexpr.args);
+
+				if (error && *error)
+					return (Datum) 0;
+
+				if (!jbv)	/* NULL or empty */
+					break;
+
+				Assert(!empty);
+
+				*resnull = false;
+
+				/* coerce scalar item to the output type */
+				if (jexpr->returning->typid == JSONOID ||
+					jexpr->returning->typid == JSONBOID)
+				{
+					/* Use result coercion from json[b] to the output type */
+					res = JsonbPGetDatum(JsonbValueToJsonb(jbv));
+					break;
+				}
+
+				/* Use coercion from SQL/JSON item type to the output type */
+				res = ExecPrepareJsonItemCoercion(jbv,
+												  op->d.jsonexpr.jsexpr->returning,
+												  &op->d.jsonexpr.coercions,
+												  &jcstate);
+
+				if (jcstate->coercion &&
+					(jcstate->coercion->via_io ||
+					 jcstate->coercion->via_populate))
+				{
+					if (error)
+					{
+						*error = true;
+						return (Datum) 0;
+					}
+					/*
+					 * Coercion via I/O means here that the cast to the target
+					 * type simply does not exist.
+					 */
+					ereport(ERROR,
+							/*
+							 * XXX Standard says about a separate error code
+							 * ERRCODE_SQL_JSON_ITEM_CANNOT_BE_CAST_TO_TARGET_TYPE
+							 * but does not define its number.
+							 */
+							(errcode(ERRCODE_SQL_JSON_SCALAR_REQUIRED),
+							 errmsg("SQL/JSON item cannot be cast to target type")));
+				}
+				else if (!jcstate->estate)
+					return res;		/* no coercion */
+
+				/* coerce using specific expression */
+				estate = jcstate->estate;
+				op->d.jsonexpr.coercion_expr->value = res;
+				op->d.jsonexpr.coercion_expr->isnull = *resnull;
+				break;
+			}
+
+		case IS_JSON_EXISTS:
+			{
+				bool		exists = JsonPathExists(item, path,
+													op->d.jsonexpr.args,
+													error);
+
+				*resnull = error && *error;
+				res = BoolGetDatum(exists);
+
+				if (!op->d.jsonexpr.result_expr)
+					return res;
+
+				/* coerce using result expression */
+				estate = op->d.jsonexpr.result_expr;
+				op->d.jsonexpr.res_expr->value = res;
+				op->d.jsonexpr.res_expr->isnull = *resnull;
+				break;
+			}
+
+		default:
+			elog(ERROR, "unrecognized SQL/JSON expression op %d", jexpr->op);
+			return (Datum) 0;
+	}
+
+	if (empty)
+	{
+		Assert(jexpr->on_empty);	/* it is not JSON_EXISTS */
+
+		if (jexpr->on_empty->btype == JSON_BEHAVIOR_ERROR)
+		{
+			if (error)
+			{
+				*error = true;
+				return (Datum) 0;
+			}
+
+			ereport(ERROR,
+					(errcode(ERRCODE_NO_SQL_JSON_ITEM),
+					 errmsg("no SQL/JSON item")));
+		}
+
+		if (jexpr->on_empty->btype == JSON_BEHAVIOR_DEFAULT)
+			/*
+			 * Execute DEFAULT expression as a coercion expression, because
+			 * its result is already coerced to the target type.
+			 */
+			estate = op->d.jsonexpr.default_on_empty;
+		else
+			/* Execute ON EMPTY behavior */
+			res = ExecEvalJsonBehavior(econtext, jexpr->on_empty,
+									   op->d.jsonexpr.default_on_empty,
+									   resnull);
+	}
+
+	return ExecEvalJsonExprSubtrans(ExecEvalJsonExprCoercion, op, econtext,
+									res, resnull, estate, error,
+									cxt->coercionInSubtrans);
+}
+
+bool
+ExecEvalJsonNeedsSubTransaction(JsonExpr *jsexpr,
+								struct JsonCoercionsState *coercions)
+{
+	if (jsexpr->on_error->btype == JSON_BEHAVIOR_ERROR)
+		return false;
+
+	if (jsexpr->op == IS_JSON_EXISTS && !jsexpr->result_coercion)
+		return false;
+
+	if (!coercions)
+		return true;
+
+	return false;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecEvalJson
+ * ----------------------------------------------------------------
+ */
+void
+ExecEvalJson(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
+{
+	ExecEvalJsonExprContext cxt;
+	JsonExpr   *jexpr = op->d.jsonexpr.jsexpr;
+	Datum		item;
+	Datum		res = (Datum) 0;
+	JsonPath   *path;
+	ListCell   *lc;
+	bool		error = false;
+	bool		needSubtrans;
+	bool		throwErrors = jexpr->on_error->btype == JSON_BEHAVIOR_ERROR;
+
+	*op->resnull = true;		/* until we get a result */
+	*op->resvalue = (Datum) 0;
+
+	if (op->d.jsonexpr.formatted_expr->isnull || op->d.jsonexpr.pathspec->isnull)
+	{
+		/* execute domain checks for NULLs */
+		(void) ExecEvalJsonExprCoercion(op, econtext, res, op->resnull,
+										NULL, NULL);
+
+		Assert(*op->resnull);
+		return;
+	}
+
+	item = op->d.jsonexpr.formatted_expr->value;
+	path = DatumGetJsonPathP(op->d.jsonexpr.pathspec->value);
+
+	/* reset JSON path variable contexts */
+	foreach(lc, op->d.jsonexpr.args)
+	{
+		JsonPathVariableEvalContext *var = lfirst(lc);
+
+		var->econtext = econtext;
+		var->evaluated = false;
+	}
+
+	needSubtrans = ExecEvalJsonNeedsSubTransaction(jexpr, &op->d.jsonexpr.coercions);
+
+	cxt.path = path;
+	cxt.error = throwErrors ? NULL : &error;
+	cxt.coercionInSubtrans = !needSubtrans && !throwErrors;
+	Assert(!needSubtrans || cxt.error);
+
+	res = ExecEvalJsonExprSubtrans(ExecEvalJsonExpr, op, econtext, item,
+								   op->resnull, &cxt, cxt.error,
+								   needSubtrans);
+
+	if (error)
+	{
+		/* Execute ON ERROR behavior */
+		res = ExecEvalJsonBehavior(econtext, jexpr->on_error,
+								   op->d.jsonexpr.default_on_error,
+								   op->resnull);
+
+		/* result is already coerced in DEFAULT behavior case */
+		if (jexpr->on_error->btype != JSON_BEHAVIOR_DEFAULT)
+			res = ExecEvalJsonExprCoercion(op, econtext, res,
+										   op->resnull,
+										   NULL, NULL);
+	}
+
+	*op->resvalue = res;
+}
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index 9e2023dc82..15c9ee44c0 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -2360,6 +2360,12 @@ llvm_compile_expr(ExprState *state)
 				LLVMBuildBr(b, opblocks[opno + 1]);
 				break;
 
+			case EEOP_JSONEXPR:
+				build_EvalXFunc(b, mod, "ExecEvalJson",
+								v_state, op, v_econtext);
+				LLVMBuildBr(b, opblocks[opno + 1]);
+				break;
+
 			case EEOP_LAST:
 				Assert(false);
 				break;
diff --git a/src/backend/jit/llvm/llvmjit_types.c b/src/backend/jit/llvm/llvmjit_types.c
index 155589a12a..b507d98ca1 100644
--- a/src/backend/jit/llvm/llvmjit_types.c
+++ b/src/backend/jit/llvm/llvmjit_types.c
@@ -133,6 +133,7 @@ void	   *referenced_functions[] =
 	ExecEvalXmlExpr,
 	ExecEvalJsonConstructor,
 	ExecEvalJsonIsPredicate,
+	ExecEvalJson,
 	MakeExpandedObjectReadOnlyInternal,
 	slot_getmissingattrs,
 	slot_getsomeattrs_int,
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 3acea2e7a5..5bb9214434 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2487,6 +2487,90 @@ _copyJsonArrayQueryConstructor(const JsonArrayQueryConstructor *from)
 	return newnode;
 }
 
+/*
+ * _copyJsonExpr
+ */
+static JsonExpr *
+_copyJsonExpr(const JsonExpr *from)
+{
+	JsonExpr    *newnode = makeNode(JsonExpr);
+
+	COPY_SCALAR_FIELD(op);
+	COPY_NODE_FIELD(formatted_expr);
+	COPY_NODE_FIELD(result_coercion);
+	COPY_NODE_FIELD(format);
+	COPY_NODE_FIELD(path_spec);
+	COPY_NODE_FIELD(passing_values);
+	COPY_NODE_FIELD(passing_names);
+	COPY_NODE_FIELD(returning);
+	COPY_NODE_FIELD(on_error);
+	COPY_NODE_FIELD(on_empty);
+	COPY_NODE_FIELD(coercions);
+	COPY_SCALAR_FIELD(wrapper);
+	COPY_SCALAR_FIELD(omit_quotes);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonCoercion
+ */
+static JsonCoercion *
+_copyJsonCoercion(const JsonCoercion *from)
+{
+	JsonCoercion *newnode = makeNode(JsonCoercion);
+
+	COPY_NODE_FIELD(expr);
+	COPY_SCALAR_FIELD(via_populate);
+	COPY_SCALAR_FIELD(via_io);
+	COPY_SCALAR_FIELD(collation);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonItemCoercions
+ */
+static JsonItemCoercions *
+_copyJsonItemCoercions(const JsonItemCoercions *from)
+{
+	JsonItemCoercions *newnode = makeNode(JsonItemCoercions);
+
+	COPY_NODE_FIELD(null);
+	COPY_NODE_FIELD(string);
+	COPY_NODE_FIELD(numeric);
+	COPY_NODE_FIELD(boolean);
+	COPY_NODE_FIELD(date);
+	COPY_NODE_FIELD(time);
+	COPY_NODE_FIELD(timetz);
+	COPY_NODE_FIELD(timestamp);
+	COPY_NODE_FIELD(timestamptz);
+	COPY_NODE_FIELD(composite);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonFuncExpr
+ */
+static JsonFuncExpr *
+_copyJsonFuncExpr(const JsonFuncExpr *from)
+{
+	JsonFuncExpr   *newnode = makeNode(JsonFuncExpr);
+
+	COPY_SCALAR_FIELD(op);
+	COPY_NODE_FIELD(common);
+	COPY_NODE_FIELD(output);
+	COPY_NODE_FIELD(on_empty);
+	COPY_NODE_FIELD(on_error);
+	COPY_SCALAR_FIELD(wrapper);
+	COPY_SCALAR_FIELD(omit_quotes);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
 /*
  * _copyJsonIsPredicate
  */
@@ -2504,6 +2588,51 @@ _copyJsonIsPredicate(const JsonIsPredicate *from)
 	return newnode;
 }
 
+/*
+ * _copyJsonBehavior
+ */
+static JsonBehavior *
+_copyJsonBehavior(const JsonBehavior *from)
+{
+	JsonBehavior   *newnode = makeNode(JsonBehavior);
+
+	COPY_SCALAR_FIELD(btype);
+	COPY_NODE_FIELD(default_expr);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonCommon
+ */
+static JsonCommon *
+_copyJsonCommon(const JsonCommon *from)
+{
+	JsonCommon	   *newnode = makeNode(JsonCommon);
+
+	COPY_NODE_FIELD(expr);
+	COPY_NODE_FIELD(pathspec);
+	COPY_STRING_FIELD(pathname);
+	COPY_NODE_FIELD(passing);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
+/*
+ * _copyJsonArgument
+ */
+static JsonArgument *
+_copyJsonArgument(const JsonArgument *from)
+{
+	JsonArgument   *newnode = makeNode(JsonArgument);
+
+	COPY_NODE_FIELD(val);
+	COPY_STRING_FIELD(name);
+
+	return newnode;
+}
+
 /* ****************************************************************
  *						pathnodes.h copy functions
  *
@@ -5554,6 +5683,27 @@ copyObjectImpl(const void *from)
 		case T_JsonIsPredicate:
 			retval = _copyJsonIsPredicate(from);
 			break;
+		case T_JsonFuncExpr:
+			retval = _copyJsonFuncExpr(from);
+			break;
+		case T_JsonExpr:
+			retval = _copyJsonExpr(from);
+			break;
+		case T_JsonCommon:
+			retval = _copyJsonCommon(from);
+			break;
+		case T_JsonBehavior:
+			retval = _copyJsonBehavior(from);
+			break;
+		case T_JsonArgument:
+			retval = _copyJsonArgument(from);
+			break;
+		case T_JsonCoercion:
+			retval = _copyJsonCoercion(from);
+			break;
+		case T_JsonItemCoercions:
+			retval = _copyJsonItemCoercions(from);
+			break;
 
 			/*
 			 * RELATION NODES
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index f14837ddcc..8287d15324 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -988,6 +988,76 @@ _equalJsonIsPredicate(const JsonIsPredicate *a,
 	return true;
 }
 
+/*
+ * _equalJsonBehavior
+ */
+static bool
+_equalJsonBehavior(const JsonBehavior *a, const JsonBehavior *b)
+{
+	COMPARE_SCALAR_FIELD(btype);
+	COMPARE_NODE_FIELD(default_expr);
+
+	return true;
+}
+
+/*
+ * _equalJsonExpr
+ */
+static bool
+_equalJsonExpr(const JsonExpr *a, const JsonExpr *b)
+{
+	COMPARE_SCALAR_FIELD(op);
+	COMPARE_NODE_FIELD(formatted_expr);
+	COMPARE_NODE_FIELD(result_coercion);
+	COMPARE_NODE_FIELD(format);
+	COMPARE_NODE_FIELD(path_spec);
+	COMPARE_NODE_FIELD(passing_values);
+	COMPARE_NODE_FIELD(passing_names);
+	COMPARE_NODE_FIELD(returning);
+	COMPARE_NODE_FIELD(on_error);
+	COMPARE_NODE_FIELD(on_empty);
+	COMPARE_NODE_FIELD(coercions);
+	COMPARE_SCALAR_FIELD(wrapper);
+	COMPARE_SCALAR_FIELD(omit_quotes);
+	COMPARE_LOCATION_FIELD(location);
+
+	return true;
+}
+
+/*
+ * _equalJsonCoercion
+ */
+static bool
+_equalJsonCoercion(const JsonCoercion *a, const JsonCoercion *b)
+{
+	COMPARE_NODE_FIELD(expr);
+	COMPARE_SCALAR_FIELD(via_populate);
+	COMPARE_SCALAR_FIELD(via_io);
+	COMPARE_SCALAR_FIELD(collation);
+
+	return true;
+}
+
+/*
+ * _equalJsonItemCoercions
+ */
+static bool
+_equalJsonItemCoercions(const JsonItemCoercions *a, const JsonItemCoercions *b)
+{
+	COMPARE_NODE_FIELD(null);
+	COMPARE_NODE_FIELD(string);
+	COMPARE_NODE_FIELD(numeric);
+	COMPARE_NODE_FIELD(boolean);
+	COMPARE_NODE_FIELD(date);
+	COMPARE_NODE_FIELD(time);
+	COMPARE_NODE_FIELD(timetz);
+	COMPARE_NODE_FIELD(timestamp);
+	COMPARE_NODE_FIELD(timestamptz);
+	COMPARE_NODE_FIELD(composite);
+
+	return true;
+}
+
 /*
  * Stuff from pathnodes.h
  */
@@ -3488,6 +3558,18 @@ equal(const void *a, const void *b)
 		case T_JsonIsPredicate:
 			retval = _equalJsonIsPredicate(a, b);
 			break;
+		case T_JsonBehavior:
+			retval = _equalJsonBehavior(a, b);
+			break;
+		case T_JsonExpr:
+			retval = _equalJsonExpr(a, b);
+			break;
+		case T_JsonCoercion:
+			retval = _equalJsonCoercion(a, b);
+			break;
+		case T_JsonItemCoercions:
+			retval = _equalJsonItemCoercions(a, b);
+			break;
 
 			/*
 			 * RELATION NODES
diff --git a/src/backend/nodes/makefuncs.c b/src/backend/nodes/makefuncs.c
index 0da1173c72..928570b22e 100644
--- a/src/backend/nodes/makefuncs.c
+++ b/src/backend/nodes/makefuncs.c
@@ -849,6 +849,21 @@ makeJsonValueExpr(Expr *expr, JsonFormat *format)
 	return jve;
 }
 
+/*
+ * makeJsonBehavior -
+ *	  creates a JsonBehavior node
+ */
+JsonBehavior *
+makeJsonBehavior(JsonBehaviorType type, Node *default_expr)
+{
+	JsonBehavior *behavior = makeNode(JsonBehavior);
+
+	behavior->btype = type;
+	behavior->default_expr = default_expr;
+
+	return behavior;
+}
+
 /*
  * makeJsonEncoding -
  *	  converts JSON encoding name to enum JsonEncoding
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 87cf0b5b95..97bd0bac6b 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -263,6 +263,12 @@ exprType(const Node *expr)
 		case T_JsonIsPredicate:
 			type = BOOLOID;
 			break;
+		case T_JsonExpr:
+			type = ((const JsonExpr *) expr)->returning->typid;
+			break;
+		case T_JsonCoercion:
+			type = exprType(((const JsonCoercion *) expr)->expr);
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
 			type = InvalidOid;	/* keep compiler quiet */
@@ -498,7 +504,11 @@ exprTypmod(const Node *expr)
 		case T_JsonValueExpr:
 			return exprTypmod((Node *) ((const JsonValueExpr *) expr)->formatted_expr);
 		case T_JsonConstructorExpr:
-			return -1; /* ((const JsonConstructorExpr *) expr)->returning->typmod; */
+			return ((const JsonConstructorExpr *) expr)->returning->typmod;
+		case T_JsonExpr:
+			return ((JsonExpr *) expr)->returning->typmod;
+		case T_JsonCoercion:
+			return exprTypmod(((const JsonCoercion *) expr)->expr);
 		default:
 			break;
 	}
@@ -989,6 +999,21 @@ exprCollation(const Node *expr)
 		case T_JsonIsPredicate:
 			coll = InvalidOid;	/* result is always an boolean type */
 			break;
+		case T_JsonExpr:
+			{
+				JsonExpr *jexpr = (JsonExpr *) expr;
+				JsonCoercion *coercion = jexpr->result_coercion;
+
+				if (!coercion)
+					coll = InvalidOid;
+				else if (coercion->expr)
+					coll = exprCollation(coercion->expr);
+				else if (coercion->via_io || coercion->via_populate)
+					coll = coercion->collation;
+				else
+					coll = InvalidOid;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
 			coll = InvalidOid;	/* keep compiler quiet */
@@ -1218,6 +1243,21 @@ exprSetCollation(Node *expr, Oid collation)
 		case T_JsonIsPredicate:
 			Assert(!OidIsValid(collation)); /* result is always boolean */
 			break;
+		case T_JsonExpr:
+			{
+				JsonExpr *jexpr = (JsonExpr *) expr;
+				JsonCoercion *coercion = jexpr->result_coercion;
+
+				if (!coercion)
+					Assert(!OidIsValid(collation));
+				else if (coercion->expr)
+					exprSetCollation(coercion->expr, collation);
+				else if (coercion->via_io || coercion->via_populate)
+					coercion->collation = collation;
+				else
+					Assert(!OidIsValid(collation));
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
 			break;
@@ -1673,6 +1713,15 @@ exprLocation(const Node *expr)
 		case T_JsonIsPredicate:
 			loc = ((const JsonIsPredicate *) expr)->location;
 			break;
+		case T_JsonExpr:
+			{
+				const JsonExpr *jsexpr = (const JsonExpr *) expr;
+
+				/* consider both function name and leftmost arg */
+				loc = leftmostLoc(jsexpr->location,
+								  exprLocation(jsexpr->formatted_expr));
+			}
+			break;
 		default:
 			/* for any other node type it's just unknown... */
 			loc = -1;
@@ -2411,6 +2460,54 @@ expression_tree_walker(Node *node,
 			break;
 		case T_JsonIsPredicate:
 			return walker(((JsonIsPredicate *) node)->expr, context);
+		case T_JsonExpr:
+			{
+				JsonExpr    *jexpr = (JsonExpr *) node;
+
+				if (walker(jexpr->formatted_expr, context))
+					return true;
+				if (walker(jexpr->result_coercion, context))
+					return true;
+				if (walker(jexpr->passing_values, context))
+					return true;
+				/* we assume walker doesn't care about passing_names */
+				if (jexpr->on_empty &&
+					walker(jexpr->on_empty->default_expr, context))
+					return true;
+				if (walker(jexpr->on_error->default_expr, context))
+					return true;
+				if (walker(jexpr->coercions, context))
+					return true;
+			}
+			break;
+		case T_JsonCoercion:
+			return walker(((JsonCoercion *) node)->expr, context);
+		case T_JsonItemCoercions:
+			{
+				JsonItemCoercions *coercions = (JsonItemCoercions *) node;
+
+				if (walker(coercions->null, context))
+					return true;
+				if (walker(coercions->string, context))
+					return true;
+				if (walker(coercions->numeric, context))
+					return true;
+				if (walker(coercions->boolean, context))
+					return true;
+				if (walker(coercions->date, context))
+					return true;
+				if (walker(coercions->time, context))
+					return true;
+				if (walker(coercions->timetz, context))
+					return true;
+				if (walker(coercions->timestamp, context))
+					return true;
+				if (walker(coercions->timestamptz, context))
+					return true;
+				if (walker(coercions->composite, context))
+					return true;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
@@ -3386,6 +3483,7 @@ expression_tree_mutator(Node *node,
 
 				return (Node *) newnode;
 			}
+			break;
 		case T_JsonIsPredicate:
 			{
 				JsonIsPredicate *pred = (JsonIsPredicate *) node;
@@ -3396,6 +3494,55 @@ expression_tree_mutator(Node *node,
 
 				return (Node *) newnode;
 			}
+			break;
+		case T_JsonExpr:
+			{
+				JsonExpr    *jexpr = (JsonExpr *) node;
+				JsonExpr    *newnode;
+
+				FLATCOPY(newnode, jexpr, JsonExpr);
+				MUTATE(newnode->path_spec, jexpr->path_spec, Node *);
+				MUTATE(newnode->formatted_expr, jexpr->formatted_expr, Node *);
+				MUTATE(newnode->result_coercion, jexpr->result_coercion, JsonCoercion *);
+				MUTATE(newnode->passing_values, jexpr->passing_values, List *);
+				/* assume mutator does not care about passing_names */
+				if (newnode->on_empty)
+					MUTATE(newnode->on_empty->default_expr,
+						   jexpr->on_empty->default_expr, Node *);
+				MUTATE(newnode->on_error->default_expr,
+					   jexpr->on_error->default_expr, Node *);
+				return (Node *) newnode;
+			}
+			break;
+		case T_JsonCoercion:
+			{
+				JsonCoercion *coercion = (JsonCoercion *) node;
+				JsonCoercion *newnode;
+
+				FLATCOPY(newnode, coercion, JsonCoercion);
+				MUTATE(newnode->expr, coercion->expr, Node *);
+				return (Node *) newnode;
+			}
+			break;
+		case T_JsonItemCoercions:
+			{
+				JsonItemCoercions *coercions = (JsonItemCoercions *) node;
+				JsonItemCoercions *newnode;
+
+				FLATCOPY(newnode, coercions, JsonItemCoercions);
+				MUTATE(newnode->null, coercions->null, JsonCoercion *);
+				MUTATE(newnode->string, coercions->string, JsonCoercion *);
+				MUTATE(newnode->numeric, coercions->numeric, JsonCoercion *);
+				MUTATE(newnode->boolean, coercions->boolean, JsonCoercion *);
+				MUTATE(newnode->date, coercions->date, JsonCoercion *);
+				MUTATE(newnode->time, coercions->time, JsonCoercion *);
+				MUTATE(newnode->timetz, coercions->timetz, JsonCoercion *);
+				MUTATE(newnode->timestamp, coercions->timestamp, JsonCoercion *);
+				MUTATE(newnode->timestamptz, coercions->timestamptz, JsonCoercion *);
+				MUTATE(newnode->composite, coercions->composite, JsonCoercion *);
+				return (Node *) newnode;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
@@ -4217,6 +4364,43 @@ raw_expression_tree_walker(Node *node,
 			break;
 		case T_JsonIsPredicate:
 			return walker(((JsonIsPredicate *) node)->expr, context);
+		case T_JsonArgument:
+			return walker(((JsonArgument *) node)->val, context);
+		case T_JsonCommon:
+			{
+				JsonCommon *jc = (JsonCommon *) node;
+
+				if (walker(jc->expr, context))
+					return true;
+				if (walker(jc->pathspec, context))
+					return true;
+				if (walker(jc->passing, context))
+					return true;
+			}
+			break;
+		case T_JsonBehavior:
+			{
+				JsonBehavior *jb = (JsonBehavior *) node;
+
+				if (jb->btype == JSON_BEHAVIOR_DEFAULT &&
+					walker(jb->default_expr, context))
+					return true;
+			}
+			break;
+		case T_JsonFuncExpr:
+			{
+				JsonFuncExpr *jfe = (JsonFuncExpr *) node;
+
+				if (walker(jfe->common, context))
+					return true;
+				if (jfe->output && walker(jfe->output, context))
+					return true;
+				if (walker(jfe->on_empty, context))
+					return true;
+				if (walker(jfe->on_error, context))
+					return true;
+			}
+			break;
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index aced2730e3..8012904870 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -1804,6 +1804,64 @@ _outJsonIsPredicate(StringInfo str, const JsonIsPredicate *node)
 	WRITE_LOCATION_FIELD(location);
 }
 
+static void
+_outJsonBehavior(StringInfo str, const JsonBehavior *node)
+{
+	WRITE_NODE_TYPE("JSONBEHAVIOR");
+
+	WRITE_ENUM_FIELD(btype, JsonBehaviorType);
+	WRITE_NODE_FIELD(default_expr);
+}
+
+static void
+_outJsonExpr(StringInfo str, const JsonExpr *node)
+{
+	WRITE_NODE_TYPE("JSONEXPR");
+
+	WRITE_ENUM_FIELD(op, JsonExprOp);
+	WRITE_NODE_FIELD(formatted_expr);
+	WRITE_NODE_FIELD(result_coercion);
+	WRITE_NODE_FIELD(format);
+	WRITE_NODE_FIELD(path_spec);
+	WRITE_NODE_FIELD(passing_values);
+	WRITE_NODE_FIELD(passing_names);
+	WRITE_NODE_FIELD(returning);
+	WRITE_NODE_FIELD(on_error);
+	WRITE_NODE_FIELD(on_empty);
+	WRITE_NODE_FIELD(coercions);
+	WRITE_ENUM_FIELD(wrapper, JsonWrapper);
+	WRITE_BOOL_FIELD(omit_quotes);
+	WRITE_LOCATION_FIELD(location);
+}
+
+static void
+_outJsonCoercion(StringInfo str, const JsonCoercion *node)
+{
+	WRITE_NODE_TYPE("JSONCOERCION");
+
+	WRITE_NODE_FIELD(expr);
+	WRITE_BOOL_FIELD(via_populate);
+	WRITE_BOOL_FIELD(via_io);
+	WRITE_OID_FIELD(collation);
+}
+
+static void
+_outJsonItemCoercions(StringInfo str, const JsonItemCoercions *node)
+{
+	WRITE_NODE_TYPE("JSONITEMCOERCIONS");
+
+	WRITE_NODE_FIELD(null);
+	WRITE_NODE_FIELD(string);
+	WRITE_NODE_FIELD(numeric);
+	WRITE_NODE_FIELD(boolean);
+	WRITE_NODE_FIELD(date);
+	WRITE_NODE_FIELD(time);
+	WRITE_NODE_FIELD(timetz);
+	WRITE_NODE_FIELD(timestamp);
+	WRITE_NODE_FIELD(timestamptz);
+	WRITE_NODE_FIELD(composite);
+}
+
 /*****************************************************************************
  *
  *	Stuff from pathnodes.h.
@@ -4592,6 +4650,18 @@ outNode(StringInfo str, const void *obj)
 			case T_JsonIsPredicate:
 				_outJsonIsPredicate(str, obj);
 				break;
+			case T_JsonBehavior:
+				_outJsonBehavior(str, obj);
+				break;
+			case T_JsonExpr:
+				_outJsonExpr(str, obj);
+				break;
+			case T_JsonCoercion:
+				_outJsonCoercion(str, obj);
+				break;
+			case T_JsonItemCoercions:
+				_outJsonItemCoercions(str, obj);
+				break;
 
 			default:
 
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 52ad6735da..2eee045db0 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -1456,6 +1456,84 @@ _readJsonConstructorExpr(void)
 	READ_DONE();
 }
 
+/*
+ * _readJsonBehavior
+ */
+static JsonBehavior *
+_readJsonBehavior(void)
+{
+	READ_LOCALS(JsonBehavior);
+
+	READ_ENUM_FIELD(btype, JsonBehaviorType);
+	READ_NODE_FIELD(default_expr);
+
+	READ_DONE();
+}
+
+/*
+ * _readJsonExpr
+ */
+static JsonExpr *
+_readJsonExpr(void)
+{
+	READ_LOCALS(JsonExpr);
+
+	READ_ENUM_FIELD(op, JsonExprOp);
+	READ_NODE_FIELD(formatted_expr);
+	READ_NODE_FIELD(result_coercion);
+	READ_NODE_FIELD(format);
+	READ_NODE_FIELD(path_spec);
+	READ_NODE_FIELD(passing_values);
+	READ_NODE_FIELD(passing_names);
+	READ_NODE_FIELD(returning);
+	READ_NODE_FIELD(on_error);
+	READ_NODE_FIELD(on_empty);
+	READ_NODE_FIELD(coercions);
+	READ_ENUM_FIELD(wrapper, JsonWrapper);
+	READ_BOOL_FIELD(omit_quotes);
+	READ_LOCATION_FIELD(location);
+
+	READ_DONE();
+}
+
+/*
+ * _readJsonCoercion
+ */
+static JsonCoercion *
+_readJsonCoercion(void)
+{
+	READ_LOCALS(JsonCoercion);
+
+	READ_NODE_FIELD(expr);
+	READ_BOOL_FIELD(via_populate);
+	READ_BOOL_FIELD(via_io);
+	READ_OID_FIELD(collation);
+
+	READ_DONE();
+}
+
+/*
+ * _readJsonItemCoercions
+ */
+static JsonItemCoercions *
+_readJsonItemCoercions(void)
+{
+	READ_LOCALS(JsonItemCoercions);
+
+	READ_NODE_FIELD(null);
+	READ_NODE_FIELD(string);
+	READ_NODE_FIELD(numeric);
+	READ_NODE_FIELD(boolean);
+	READ_NODE_FIELD(date);
+	READ_NODE_FIELD(time);
+	READ_NODE_FIELD(timetz);
+	READ_NODE_FIELD(timestamp);
+	READ_NODE_FIELD(timestamptz);
+	READ_NODE_FIELD(composite);
+
+	READ_DONE();
+}
+
 /*
  * _readJsonIsPredicate
  */
@@ -3064,6 +3142,14 @@ parseNodeString(void)
 		return_value = _readJsonConstructorExpr();
 	else if (MATCH("JSONISPREDICATE", 15))
 		return_value = _readJsonIsPredicate();
+	else if (MATCH("JSONBEHAVIOR", 12))
+		return_value = _readJsonBehavior();
+	else if (MATCH("JSONEXPR", 8))
+		return_value = _readJsonExpr();
+	else if (MATCH("JSONCOERCION", 12))
+		return_value = _readJsonCoercion();
+	else if (MATCH("JSONITEMCOERCIONS", 17))
+		return_value = _readJsonItemCoercions();
 	else
 	{
 		elog(ERROR, "badly formatted node string \"%.32s\"...", token);
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 1e4d404f02..5033e8c87a 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -4540,7 +4540,8 @@ cost_qual_eval_walker(Node *node, cost_qual_eval_context *context)
 			 IsA(node, SQLValueFunction) ||
 			 IsA(node, XmlExpr) ||
 			 IsA(node, CoerceToDomain) ||
-			 IsA(node, NextValueExpr))
+			 IsA(node, NextValueExpr) ||
+			 IsA(node, JsonExpr))
 	{
 		/* Treat all these as having cost 1 */
 		context->total.per_tuple += cpu_operator_cost;
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index f46786231e..c1951c1caf 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -28,6 +28,7 @@
 #include "catalog/pg_type.h"
 #include "executor/executor.h"
 #include "executor/functions.h"
+#include "executor/execExpr.h"
 #include "funcapi.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
@@ -52,6 +53,7 @@
 #include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
+#include "utils/jsonpath.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
 #include "utils/syscache.h"
@@ -404,6 +406,24 @@ contain_mutable_functions_walker(Node *node, void *context)
 		/* Check all subnodes */
 	}
 
+	if (IsA(node, JsonExpr))
+	{
+		JsonExpr   *jexpr = castNode(JsonExpr, node);
+		Const	   *cnst;
+
+		if (!IsA(jexpr->path_spec, Const))
+			return true;
+
+		cnst = castNode(Const, jexpr->path_spec);
+
+		Assert(cnst->consttype == JSONPATHOID);
+		if (cnst->constisnull)
+			return false;
+
+		return jspIsMutable(DatumGetJsonPathP(cnst->constvalue),
+							jexpr->passing_names, jexpr->passing_values);
+	}
+
 	if (IsA(node, SQLValueFunction))
 	{
 		/* all variants of SQLValueFunction are stable */
@@ -875,6 +895,18 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
 								 context, 0);
 	}
 
+	/* JsonExpr is parallel-unsafe if subtransactions can be used. */
+	else if (IsA(node, JsonExpr))
+	{
+		JsonExpr  *jsexpr = (JsonExpr *) node;
+
+		if (ExecEvalJsonNeedsSubTransaction(jsexpr, NULL))
+		{
+			context->max_hazard = PROPARALLEL_UNSAFE;
+			return true;
+		}
+	}
+
 	/* Recurse to check arguments */
 	return expression_tree_walker(node,
 								  max_parallel_hazard_walker,
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 7258dbd52f..0e5b0d695f 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -259,6 +259,13 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	struct SelectLimit	*selectlimit;
 	SetQuantifier	 setquantifier;
 	struct GroupClause  *groupclause;
+	JsonBehavior		*jsbehavior;
+	struct
+	{
+		JsonBehavior		*on_empty;
+		JsonBehavior		*on_error;
+	} 					on_behavior;
+	JsonQuotes			js_quotes;
 }
 
 %type <node>	stmt toplevel_stmt schema_stmt routine_body_stmt
@@ -614,7 +621,14 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 					json_representation
 					json_value_expr
 					json_func_expr
+					json_value_func_expr
+					json_query_expr
+					json_exists_predicate
+					json_api_common_syntax
+					json_context_item
+					json_argument
 					json_output_clause_opt
+					json_returning_clause_opt
 					json_value_constructor
 					json_object_constructor
 					json_object_constructor_args
@@ -626,15 +640,43 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 					json_aggregate_func
 					json_object_aggregate_constructor
 					json_array_aggregate_constructor
+					json_path_specification
 
 %type <list>		json_name_and_value_list
 					json_value_expr_list
 					json_array_aggregate_order_by_clause_opt
+					json_arguments
+					json_passing_clause_opt
+
+%type <str>			json_table_path_name
+					json_as_path_name_clause_opt
 
 %type <ival>		json_encoding
 					json_encoding_clause_opt
+					json_wrapper_clause_opt
+					json_wrapper_behavior
+					json_conditional_or_unconditional_opt
 					json_predicate_type_constraint_opt
 
+%type <jsbehavior>	json_behavior_error
+					json_behavior_null
+					json_behavior_true
+					json_behavior_false
+					json_behavior_unknown
+					json_behavior_empty_array
+					json_behavior_empty_object
+					json_behavior_default
+					json_value_behavior
+					json_query_behavior
+					json_exists_error_behavior
+					json_exists_error_clause_opt
+
+%type <on_behavior> json_value_on_behavior_clause_opt
+					json_query_on_behavior_clause_opt
+
+%type <js_quotes>	json_quotes_behavior
+					json_quotes_clause_opt
+
 %type <boolean>		json_key_uniqueness_constraint_opt
 					json_object_constructor_null_clause_opt
 					json_array_constructor_null_clause_opt
@@ -674,7 +716,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	CACHE CALL CALLED CASCADE CASCADED CASE CAST CATALOG_P CHAIN CHAR_P
 	CHARACTER CHARACTERISTICS CHECK CHECKPOINT CLASS CLOSE
 	CLUSTER COALESCE COLLATE COLLATION COLUMN COLUMNS COMMENT COMMENTS COMMIT
-	COMMITTED COMPRESSION CONCURRENTLY CONFIGURATION CONFLICT
+	COMMITTED COMPRESSION CONCURRENTLY CONDITIONAL CONFIGURATION CONFLICT
 	CONNECTION CONSTRAINT CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY
 	COST CREATE CROSS CSV CUBE CURRENT_P
 	CURRENT_CATALOG CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
@@ -685,8 +727,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	DETACH DICTIONARY DISABLE_P DISCARD DISTINCT DO DOCUMENT_P DOMAIN_P
 	DOUBLE_P DROP
 
-	EACH ELSE ENABLE_P ENCODING ENCRYPTED END_P ENUM_P ESCAPE EVENT EXCEPT
-	EXCLUDE EXCLUDING EXCLUSIVE EXECUTE EXISTS EXPLAIN EXPRESSION
+	EACH ELSE EMPTY_P ENABLE_P ENCODING ENCRYPTED END_P ENUM_P ERROR_P ESCAPE
+	EVENT EXCEPT EXCLUDE EXCLUDING EXCLUSIVE EXECUTE EXISTS EXPLAIN EXPRESSION
 	EXTENSION EXTERNAL EXTRACT
 
 	FALSE_P FAMILY FETCH FILTER FINALIZE FIRST_P FLOAT_P FOLLOWING FOR
@@ -701,7 +743,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	INNER_P INOUT INPUT_P INSENSITIVE INSERT INSTEAD INT_P INTEGER
 	INTERSECT INTERVAL INTO INVOKER IS ISNULL ISOLATION
 
-	JOIN JSON JSON_ARRAY JSON_ARRAYAGG JSON_OBJECT JSON_OBJECTAGG
+	JOIN JSON JSON_ARRAY JSON_ARRAYAGG JSON_EXISTS JSON_OBJECT JSON_OBJECTAGG
+	JSON_QUERY JSON_VALUE
 
 	KEY KEYS KEEP
 
@@ -716,7 +759,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	NOT NOTHING NOTIFY NOTNULL NOWAIT NULL_P NULLIF
 	NULLS_P NUMERIC
 
-	OBJECT_P OF OFF OFFSET OIDS OLD ON ONLY OPERATOR OPTION OPTIONS OR
+	OBJECT_P OF OFF OFFSET OIDS OLD OMIT ON ONLY OPERATOR OPTION OPTIONS OR
 	ORDER ORDINALITY OTHERS OUT_P OUTER_P
 	OVER OVERLAPS OVERLAY OVERRIDING OWNED OWNER
 
@@ -724,7 +767,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	POSITION PRECEDING PRECISION PRESERVE PREPARE PREPARED PRIMARY
 	PRIOR PRIVILEGES PROCEDURAL PROCEDURE PROCEDURES PROGRAM PUBLICATION
 
-	QUOTE
+	QUOTE QUOTES
 
 	RANGE READ REAL REASSIGN RECHECK RECURSIVE REF REFERENCES REFERENCING
 	REFRESH REINDEX RELATIVE_P RELEASE RENAME REPEATABLE REPLACE REPLICA
@@ -734,7 +777,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	SAVEPOINT SCALAR SCHEMA SCHEMAS SCROLL SEARCH SECOND_P SECURITY SELECT
 	SEQUENCE SEQUENCES SERIALIZABLE SERVER SESSION SESSION_USER SET SETS SETOF
 	SHARE SHOW SIMILAR SIMPLE SKIP SMALLINT SNAPSHOT SOME SQL_P STABLE STANDALONE_P
-	START STATEMENT STATISTICS STDIN STDOUT STORAGE STORED STRICT_P STRIP_P
+	START STATEMENT STATISTICS STDIN STDOUT STORAGE STORED STRICT_P STRING STRIP_P
 	SUBSCRIPTION SUBSTRING SUPPORT SYMMETRIC SYSID SYSTEM_P
 
 	TABLE TABLES TABLESAMPLE TABLESPACE TEMP TEMPLATE TEMPORARY TEXT_P THEN
@@ -742,7 +785,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	TREAT TRIGGER TRIM TRUE_P
 	TRUNCATE TRUSTED TYPE_P TYPES_P
 
-	UESCAPE UNBOUNDED UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
+	UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
 	UNLISTEN UNLOGGED UNTIL UPDATE USER USING
 
 	VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
@@ -821,7 +864,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
  * Using the same precedence as IDENT seems right for the reasons given above.
  */
 %nonassoc	UNBOUNDED		/* ideally would have same precedence as IDENT */
-%nonassoc	ABSENT UNIQUE JSON
+%nonassoc	ERROR_P EMPTY_P DEFAULT ABSENT /* JSON error/empty behavior */
+%nonassoc	FALSE_P KEEP OMIT PASSING TRUE_P UNKNOWN UNIQUE JSON
 %nonassoc	IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
 %left		Op OPERATOR		/* multi-character ops and user-defined operators */
 %left		'+' '-'
@@ -15134,6 +15178,80 @@ opt_asymmetric: ASYMMETRIC
 /* SQL/JSON support */
 json_func_expr:
 			json_value_constructor
+			| json_value_func_expr
+			| json_query_expr
+			| json_exists_predicate
+		;
+
+
+json_value_func_expr:
+			JSON_VALUE '('
+				json_api_common_syntax
+				json_returning_clause_opt
+				json_value_on_behavior_clause_opt
+			')'
+				{
+					JsonFuncExpr *n = makeNode(JsonFuncExpr);
+					n->op = IS_JSON_VALUE;
+					n->common = (JsonCommon *) $3;
+					n->output = (JsonOutput *) $4;
+					n->on_empty = $5.on_empty;
+					n->on_error = $5.on_error;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_api_common_syntax:
+			json_context_item ',' json_path_specification
+			json_as_path_name_clause_opt
+			json_passing_clause_opt
+				{
+					JsonCommon *n = makeNode(JsonCommon);
+					n->expr = (JsonValueExpr *) $1;
+					n->pathspec = $3;
+					n->pathname = $4;
+					n->passing = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_context_item:
+			json_value_expr							{ $$ = $1; }
+		;
+
+json_path_specification:
+			a_expr									{ $$ = $1; }
+		;
+
+json_as_path_name_clause_opt:
+			 AS json_table_path_name				{ $$ = $2; }
+			 | /* EMPTY */							{ $$ = NULL; }
+		;
+
+json_table_path_name:
+			name									{ $$ = $1; }
+		;
+
+json_passing_clause_opt:
+			PASSING json_arguments					{ $$ = $2; }
+			| /* EMPTY */							{ $$ = NIL; }
+		;
+
+json_arguments:
+			json_argument							{ $$ = list_make1($1); }
+			| json_arguments ',' json_argument		{ $$ = lappend($1, $3); }
+		;
+
+json_argument:
+			json_value_expr AS ColLabel
+			{
+				JsonArgument *n = makeNode(JsonArgument);
+				n->val = (JsonValueExpr *) $1;
+				n->name = $3;
+				$$ = (Node *) n;
+			}
 		;
 
 json_value_expr:
@@ -15172,6 +15290,153 @@ json_encoding:
 			name									{ $$ = makeJsonEncoding($1); }
 		;
 
+json_behavior_error:
+			ERROR_P		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_ERROR, NULL); }
+		;
+
+json_behavior_null:
+			NULL_P		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_NULL, NULL); }
+		;
+
+json_behavior_true:
+			TRUE_P		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_TRUE, NULL); }
+		;
+
+json_behavior_false:
+			FALSE_P		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_FALSE, NULL); }
+		;
+
+json_behavior_unknown:
+			UNKNOWN		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_UNKNOWN, NULL); }
+		;
+
+json_behavior_empty_array:
+			EMPTY_P ARRAY	{ $$ = makeJsonBehavior(JSON_BEHAVIOR_EMPTY_ARRAY, NULL); }
+			/* non-standard, for Oracle compatibility only */
+			| EMPTY_P 		{ $$ = makeJsonBehavior(JSON_BEHAVIOR_EMPTY_ARRAY, NULL); }
+		;
+
+json_behavior_empty_object:
+			EMPTY_P OBJECT_P	{ $$ = makeJsonBehavior(JSON_BEHAVIOR_EMPTY_OBJECT, NULL); }
+		;
+
+json_behavior_default:
+			DEFAULT a_expr	{ $$ = makeJsonBehavior(JSON_BEHAVIOR_DEFAULT, $2); }
+		;
+
+
+json_value_behavior:
+			json_behavior_null
+			| json_behavior_error
+			| json_behavior_default
+		;
+
+json_value_on_behavior_clause_opt:
+			json_value_behavior ON EMPTY_P
+									{ $$.on_empty = $1; $$.on_error = NULL; }
+			| json_value_behavior ON EMPTY_P json_value_behavior ON ERROR_P
+									{ $$.on_empty = $1; $$.on_error = $4; }
+			| json_value_behavior ON ERROR_P
+									{ $$.on_empty = NULL; $$.on_error = $1; }
+			|  /* EMPTY */
+									{ $$.on_empty = NULL; $$.on_error = NULL; }
+		;
+
+json_query_expr:
+			JSON_QUERY '('
+				json_api_common_syntax
+				json_output_clause_opt
+				json_wrapper_clause_opt
+				json_quotes_clause_opt
+				json_query_on_behavior_clause_opt
+			')'
+				{
+					JsonFuncExpr *n = makeNode(JsonFuncExpr);
+					n->op = IS_JSON_QUERY;
+					n->common = (JsonCommon *) $3;
+					n->output = (JsonOutput *) $4;
+					n->wrapper = $5;
+					if (n->wrapper != JSW_NONE && $6 != JS_QUOTES_UNSPEC)
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used"),
+								 parser_errposition(@6)));
+					n->omit_quotes = $6 == JS_QUOTES_OMIT;
+					n->on_empty = $7.on_empty;
+					n->on_error = $7.on_error;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+		;
+
+json_wrapper_clause_opt:
+			json_wrapper_behavior WRAPPER			{ $$ = $1; }
+			| /* EMPTY */							{ $$ = 0; }
+		;
+
+json_wrapper_behavior:
+			WITHOUT array_opt						{ $$ = JSW_NONE; }
+			| WITH json_conditional_or_unconditional_opt array_opt { $$ = $2; }
+		;
+
+array_opt:
+			ARRAY									{ }
+			| /* EMPTY */							{ }
+		;
+
+json_conditional_or_unconditional_opt:
+			CONDITIONAL								{ $$ = JSW_CONDITIONAL; }
+			| UNCONDITIONAL							{ $$ = JSW_UNCONDITIONAL; }
+			| /* EMPTY */							{ $$ = JSW_UNCONDITIONAL; }
+		;
+
+json_quotes_clause_opt:
+			json_quotes_behavior QUOTES json_on_scalar_string_opt { $$ = $1; }
+			| /* EMPTY */							{ $$ = JS_QUOTES_UNSPEC; }
+		;
+
+json_quotes_behavior:
+			KEEP									{ $$ = JS_QUOTES_KEEP; }
+			| OMIT									{ $$ = JS_QUOTES_OMIT; }
+		;
+
+json_on_scalar_string_opt:
+			ON SCALAR STRING						{ }
+			| /* EMPTY */							{ }
+		;
+
+json_query_behavior:
+			json_behavior_error
+			| json_behavior_null
+			| json_behavior_empty_array
+			| json_behavior_empty_object
+			| json_behavior_default
+		;
+
+json_query_on_behavior_clause_opt:
+			json_query_behavior ON EMPTY_P
+									{ $$.on_empty = $1; $$.on_error = NULL; }
+			| json_query_behavior ON EMPTY_P json_query_behavior ON ERROR_P
+									{ $$.on_empty = $1; $$.on_error = $4; }
+			| json_query_behavior ON ERROR_P
+									{ $$.on_empty = NULL; $$.on_error = $1; }
+			|  /* EMPTY */
+									{ $$.on_empty = NULL; $$.on_error = NULL; }
+		;
+
+json_returning_clause_opt:
+			RETURNING Typename
+				{
+					JsonOutput *n = makeNode(JsonOutput);
+					n->typeName = $2;
+					n->returning = makeNode(JsonReturning);
+					n->returning->format =
+						makeJsonFormat(JS_FORMAT_DEFAULT, JS_ENC_DEFAULT, @2);
+					$$ = (Node *) n;
+				}
+			| /* EMPTY */							{ $$ = NULL; }
+			;
+
 json_output_clause_opt:
 			RETURNING Typename json_format_clause_opt
 				{
@@ -15184,6 +15449,35 @@ json_output_clause_opt:
 			| /* EMPTY */							{ $$ = NULL; }
 			;
 
+json_exists_predicate:
+			JSON_EXISTS '('
+				json_api_common_syntax
+				json_returning_clause_opt
+				json_exists_error_clause_opt
+			')'
+				{
+					JsonFuncExpr *p = makeNode(JsonFuncExpr);
+					p->op = IS_JSON_EXISTS;
+					p->common = (JsonCommon *) $3;
+					p->output = (JsonOutput *) $4;
+					p->on_error = $5;
+					p->location = @1;
+					$$ = (Node *) p;
+				}
+		;
+
+json_exists_error_clause_opt:
+			json_exists_error_behavior ON ERROR_P		{ $$ = $1; }
+			| /* EMPTY */								{ $$ = NULL; }
+		;
+
+json_exists_error_behavior:
+			json_behavior_error
+			| json_behavior_true
+			| json_behavior_false
+			| json_behavior_unknown
+		;
+
 json_value_constructor:
 			json_object_constructor
 			| json_array_constructor
@@ -15875,6 +16169,7 @@ unreserved_keyword:
 			| COMMIT
 			| COMMITTED
 			| COMPRESSION
+			| CONDITIONAL
 			| CONFIGURATION
 			| CONFLICT
 			| CONNECTION
@@ -15911,10 +16206,12 @@ unreserved_keyword:
 			| DOUBLE_P
 			| DROP
 			| EACH
+			| EMPTY_P
 			| ENABLE_P
 			| ENCODING
 			| ENCRYPTED
 			| ENUM_P
+			| ERROR_P
 			| ESCAPE
 			| EVENT
 			| EXCLUDE
@@ -15964,6 +16261,7 @@ unreserved_keyword:
 			| INVOKER
 			| ISOLATION
 			| JSON
+			| KEEP
 			| KEY
 			| KEYS
 			| LABEL
@@ -16008,6 +16306,7 @@ unreserved_keyword:
 			| OFF
 			| OIDS
 			| OLD
+			| OMIT
 			| OPERATOR
 			| OPTION
 			| OPTIONS
@@ -16037,6 +16336,7 @@ unreserved_keyword:
 			| PROGRAM
 			| PUBLICATION
 			| QUOTE
+			| QUOTES
 			| RANGE
 			| READ
 			| REASSIGN
@@ -16118,6 +16418,7 @@ unreserved_keyword:
 			| UESCAPE
 			| UNBOUNDED
 			| UNCOMMITTED
+			| UNCONDITIONAL
 			| UNENCRYPTED
 			| UNKNOWN
 			| UNLISTEN
@@ -16177,8 +16478,11 @@ col_name_keyword:
 			| INTERVAL
 			| JSON_ARRAY
 			| JSON_ARRAYAGG
+			| JSON_EXISTS
 			| JSON_OBJECT
 			| JSON_OBJECTAGG
+			| JSON_QUERY
+			| JSON_VALUE
 			| LEAST
 			| NATIONAL
 			| NCHAR
@@ -16246,6 +16550,7 @@ type_func_name_keyword:
 			| OVERLAPS
 			| RIGHT
 			| SIMILAR
+			| STRING
 			| TABLESAMPLE
 			| VERBOSE
 		;
@@ -16410,6 +16715,7 @@ bare_label_keyword:
 			| COMMITTED
 			| COMPRESSION
 			| CONCURRENTLY
+			| CONDITIONAL
 			| CONFIGURATION
 			| CONFLICT
 			| CONNECTION
@@ -16462,11 +16768,13 @@ bare_label_keyword:
 			| DROP
 			| EACH
 			| ELSE
+			| EMPTY_P
 			| ENABLE_P
 			| ENCODING
 			| ENCRYPTED
 			| END_P
 			| ENUM_P
+			| ERROR_P
 			| ESCAPE
 			| EVENT
 			| EXCLUDE
@@ -16535,8 +16843,11 @@ bare_label_keyword:
 			| JSON
 			| JSON_ARRAY
 			| JSON_ARRAYAGG
+			| JSON_EXISTS
 			| JSON_OBJECT
 			| JSON_OBJECTAGG
+			| JSON_QUERY
+			| JSON_VALUE
 			| KEEP
 			| KEY
 			| KEYS
@@ -16596,6 +16907,7 @@ bare_label_keyword:
 			| OFF
 			| OIDS
 			| OLD
+			| OMIT
 			| ONLY
 			| OPERATOR
 			| OPTION
@@ -16632,6 +16944,7 @@ bare_label_keyword:
 			| PROGRAM
 			| PUBLICATION
 			| QUOTE
+			| QUOTES
 			| RANGE
 			| READ
 			| REAL
@@ -16700,6 +17013,7 @@ bare_label_keyword:
 			| STORAGE
 			| STORED
 			| STRICT_P
+			| STRING
 			| STRIP_P
 			| SUBSCRIPTION
 			| SUBSTRING
@@ -16733,6 +17047,7 @@ bare_label_keyword:
 			| UESCAPE
 			| UNBOUNDED
 			| UNCOMMITTED
+			| UNCONDITIONAL
 			| UNENCRYPTED
 			| UNIQUE
 			| UNKNOWN
diff --git a/src/backend/parser/parse_collate.c b/src/backend/parser/parse_collate.c
index 4133526f04..9db8967c60 100644
--- a/src/backend/parser/parse_collate.c
+++ b/src/backend/parser/parse_collate.c
@@ -690,6 +690,10 @@ assign_collations_walker(Node *node, assign_collations_context *context)
 															&loccontext);
 						}
 						break;
+					case T_JsonExpr:
+						/* Context item and PASSING arguments are already
+						 * marked with collations in parse_expr.c. */
+						break;
 					default:
 
 						/*
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 3e38ba46ac..59aaee83e1 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -86,6 +86,8 @@ static Node *transformJsonArrayQueryConstructor(ParseState *pstate,
 static Node *transformJsonObjectAgg(ParseState *pstate, JsonObjectAgg *agg);
 static Node *transformJsonArrayAgg(ParseState *pstate, JsonArrayAgg *agg);
 static Node *transformJsonIsPredicate(ParseState *pstate, JsonIsPredicate *p);
+static Node *transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *p);
+static Node *transformJsonValueExpr(ParseState *pstate, JsonValueExpr *jve);
 static Node *make_row_comparison_op(ParseState *pstate, List *opname,
 									List *largs, List *rargs, int location);
 static Node *make_row_distinct_op(ParseState *pstate, List *opname,
@@ -337,6 +339,14 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 			result = transformJsonIsPredicate(pstate, (JsonIsPredicate *) expr);
 			break;
 
+		case T_JsonFuncExpr:
+			result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
+			break;
+
+		case T_JsonValueExpr:
+			result = transformJsonValueExpr(pstate, (JsonValueExpr *) expr);
+			break;
+
 		default:
 			/* should not reach here */
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -3209,8 +3219,8 @@ makeCaseTestExpr(Node *expr)
  * default format otherwise.
  */
 static Node *
-transformJsonValueExpr(ParseState *pstate, JsonValueExpr *ve,
-					   JsonFormatType default_format)
+transformJsonValueExprExt(ParseState *pstate, JsonValueExpr *ve,
+						  JsonFormatType default_format, bool isarg)
 {
 	Node	   *expr = transformExprRecurse(pstate, (Node *) ve->raw_expr);
 	Node	   *rawexpr;
@@ -3229,6 +3239,8 @@ transformJsonValueExpr(ParseState *pstate, JsonValueExpr *ve,
 
 	get_type_category_preferred(exprtype, &typcategory, &typispreferred);
 
+	rawexpr = expr;
+
 	if (ve->format->format != JS_FORMAT_DEFAULT)
 	{
 		if (ve->format->encoding != JS_ENC_DEFAULT && exprtype != BYTEAOID)
@@ -3247,12 +3259,44 @@ transformJsonValueExpr(ParseState *pstate, JsonValueExpr *ve,
 		else
 			format = ve->format->format;
 	}
+	else if (isarg)
+	{
+		/* Pass SQL/JSON item types directly without conversion to json[b]. */
+		switch (exprtype)
+		{
+			case TEXTOID:
+			case NUMERICOID:
+			case BOOLOID:
+			case INT2OID:
+			case INT4OID:
+			case INT8OID:
+			case FLOAT4OID:
+			case FLOAT8OID:
+			case DATEOID:
+			case TIMEOID:
+			case TIMETZOID:
+			case TIMESTAMPOID:
+			case TIMESTAMPTZOID:
+				return expr;
+
+			default:
+				if (typcategory == TYPCATEGORY_STRING)
+					return coerce_to_specific_type(pstate, expr, TEXTOID,
+												   "JSON_VALUE_EXPR");
+				/* else convert argument to json[b] type */
+				break;
+		}
+
+		format = default_format;
+	}
 	else if (exprtype == JSONOID || exprtype == JSONBOID)
 		format = JS_FORMAT_DEFAULT;	/* do not format json[b] types */
 	else
 		format = default_format;
 
-	if (format != JS_FORMAT_DEFAULT)
+	if (format == JS_FORMAT_DEFAULT)
+		expr = rawexpr;
+	else
 	{
 		Oid			targettype = format == JS_FORMAT_JSONB ? JSONBOID : JSONOID;
 		Node	   *orig = makeCaseTestExpr(expr);
@@ -3260,7 +3304,7 @@ transformJsonValueExpr(ParseState *pstate, JsonValueExpr *ve,
 
 		expr = orig;
 
-		if (exprtype != BYTEAOID && typcategory != TYPCATEGORY_STRING)
+		if (!isarg && exprtype != BYTEAOID && typcategory != TYPCATEGORY_STRING)
 			ereport(ERROR,
 					(errcode(ERRCODE_DATATYPE_MISMATCH),
 					 errmsg(ve->format->format == JS_FORMAT_DEFAULT ?
@@ -3311,6 +3355,24 @@ transformJsonValueExpr(ParseState *pstate, JsonValueExpr *ve,
 	return expr;
 }
 
+/*
+ * Transform JSON value expression using FORMAT JSON by default.
+ */
+static Node *
+transformJsonValueExpr(ParseState *pstate, JsonValueExpr *jve)
+{
+	return transformJsonValueExprExt(pstate, jve, JS_FORMAT_JSON, false);
+}
+
+/*
+ * Transform JSON value expression using unspecified format by default.
+ */
+static Node *
+transformJsonValueExprDefault(ParseState *pstate, JsonValueExpr *jve)
+{
+	return transformJsonValueExprExt(pstate, jve, JS_FORMAT_DEFAULT, false);
+}
+
 /*
  * Checks specified output format for its applicability to the target type.
  */
@@ -3574,8 +3636,7 @@ transformJsonObjectConstructor(ParseState *pstate, JsonObjectConstructor *ctor)
 		{
 			JsonKeyValue *kv = castNode(JsonKeyValue, lfirst(lc));
 			Node	   *key = transformExprRecurse(pstate, (Node *) kv->key);
-			Node	   *val = transformJsonValueExpr(pstate, kv->value,
-													 JS_FORMAT_DEFAULT);
+			Node	   *val = transformJsonValueExprDefault(pstate, kv->value);
 
 			args = lappend(args, key);
 			args = lappend(args, val);
@@ -3753,7 +3814,7 @@ transformJsonObjectAgg(ParseState *pstate, JsonObjectAgg *agg)
 	Oid			aggtype;
 
 	key = transformExprRecurse(pstate, (Node *) agg->arg->key);
-	val = transformJsonValueExpr(pstate, agg->arg->value, JS_FORMAT_DEFAULT);
+	val = transformJsonValueExprDefault(pstate, agg->arg->value);
 	args = list_make2(key, val);
 
 	returning = transformJsonConstructorOutput(pstate, agg->constructor->output,
@@ -3811,7 +3872,7 @@ transformJsonArrayAgg(ParseState *pstate, JsonArrayAgg *agg)
 	const char *aggfnname;
 	Oid			aggtype;
 
-	arg = transformJsonValueExpr(pstate, agg->arg, JS_FORMAT_DEFAULT);
+	arg = transformJsonValueExprDefault(pstate, agg->arg);
 
 	returning = transformJsonConstructorOutput(pstate, agg->constructor->output,
 											   list_make1(arg));
@@ -3859,8 +3920,7 @@ transformJsonArrayConstructor(ParseState *pstate, JsonArrayConstructor *ctor)
 		foreach(lc, ctor->exprs)
 		{
 			JsonValueExpr *jsval = castNode(JsonValueExpr, lfirst(lc));
-			Node	   *val = transformJsonValueExpr(pstate, jsval,
-													 JS_FORMAT_DEFAULT);
+			Node	   *val = transformJsonValueExprDefault(pstate, jsval);
 
 			args = lappend(args, val);
 		}
@@ -3943,3 +4003,413 @@ transformJsonIsPredicate(ParseState *pstate, JsonIsPredicate *pred)
 	return makeJsonIsPredicate(expr, NULL, pred->value_type,
 							   pred->unique_keys, pred->location);
 }
+
+/*
+ * Transform a JSON PASSING clause.
+ */
+static void
+transformJsonPassingArgs(ParseState *pstate, JsonFormatType format, List *args,
+						 List **passing_values, List **passing_names)
+{
+	ListCell   *lc;
+
+	*passing_values = NIL;
+	*passing_names = NIL;
+
+	foreach(lc, args)
+	{
+		JsonArgument *arg = castNode(JsonArgument, lfirst(lc));
+		Node	   *expr = transformJsonValueExprExt(pstate, arg->val,
+													 format, true);
+
+		assign_expr_collations(pstate, expr);
+
+		*passing_values = lappend(*passing_values, expr);
+		*passing_names = lappend(*passing_names, makeString(arg->name));
+	}
+}
+
+/*
+ * Transform a JSON BEHAVIOR clause.
+ */
+static JsonBehavior *
+transformJsonBehavior(ParseState *pstate, JsonBehavior *behavior,
+					  JsonBehaviorType default_behavior)
+{
+	JsonBehaviorType behavior_type;
+	Node	   *default_expr;
+
+	behavior_type = behavior ? behavior->btype : default_behavior;
+	default_expr = behavior_type != JSON_BEHAVIOR_DEFAULT ? NULL :
+		transformExprRecurse(pstate, behavior->default_expr);
+
+	return makeJsonBehavior(behavior_type, default_expr);
+}
+
+/*
+ * Common code for JSON_VALUE, JSON_QUERY, JSON_EXISTS transformation
+ * into a JsonExpr node.
+ */
+static JsonExpr *
+transformJsonExprCommon(ParseState *pstate, JsonFuncExpr *func)
+{
+	JsonExpr   *jsexpr = makeNode(JsonExpr);
+	Node	   *pathspec;
+	JsonFormatType format;
+
+	if (func->common->pathname)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("JSON_TABLE path name is not allowed here"),
+				 parser_errposition(pstate, func->location)));
+
+	jsexpr->location = func->location;
+	jsexpr->op = func->op;
+	jsexpr->formatted_expr = transformJsonValueExpr(pstate, func->common->expr);
+
+	assign_expr_collations(pstate, jsexpr->formatted_expr);
+
+	/* format is determined by context item type */
+	format = exprType(jsexpr->formatted_expr) == JSONBOID ? JS_FORMAT_JSONB : JS_FORMAT_JSON;
+
+	jsexpr->result_coercion = NULL;
+	jsexpr->omit_quotes = false;
+
+	jsexpr->format = func->common->expr->format;
+
+	pathspec = transformExprRecurse(pstate, func->common->pathspec);
+
+	jsexpr->path_spec =
+		coerce_to_target_type(pstate, pathspec, exprType(pathspec),
+							  JSONPATHOID, -1,
+							  COERCION_EXPLICIT, COERCE_IMPLICIT_CAST,
+							  exprLocation(pathspec));
+	if (!jsexpr->path_spec)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("JSON path expression must be type %s, not type %s",
+						"jsonpath", format_type_be(exprType(pathspec))),
+				 parser_errposition(pstate, exprLocation(pathspec))));
+
+	/* transform and coerce to json[b] passing arguments */
+	transformJsonPassingArgs(pstate, format, func->common->passing,
+							 &jsexpr->passing_values, &jsexpr->passing_names);
+
+	if (func->op != IS_JSON_EXISTS)
+		jsexpr->on_empty = transformJsonBehavior(pstate, func->on_empty,
+												 JSON_BEHAVIOR_NULL);
+
+	jsexpr->on_error = transformJsonBehavior(pstate, func->on_error,
+											 func->op == IS_JSON_EXISTS ?
+											 JSON_BEHAVIOR_FALSE :
+											 JSON_BEHAVIOR_NULL);
+
+	return jsexpr;
+}
+
+/*
+ * Assign default JSON returning type from the specified format or from
+ * the context item type.
+ */
+static void
+assignDefaultJsonReturningType(Node *context_item, JsonFormat *context_format,
+							   JsonReturning *ret)
+{
+	bool		is_jsonb;
+
+	ret->format = copyObject(context_format);
+
+	if (ret->format->format == JS_FORMAT_DEFAULT)
+		is_jsonb = exprType(context_item) == JSONBOID;
+	else
+		is_jsonb = ret->format->format == JS_FORMAT_JSONB;
+
+	ret->typid = is_jsonb ? JSONBOID : JSONOID;
+	ret->typmod = -1;
+}
+
+/*
+ * Try to coerce expression to the output type or
+ * use json_populate_type() for composite, array and domain types or
+ * use coercion via I/O.
+ */
+static JsonCoercion *
+coerceJsonExpr(ParseState *pstate, Node *expr, const JsonReturning *returning)
+{
+	char		typtype;
+	JsonCoercion *coercion = makeNode(JsonCoercion);
+
+	coercion->expr = coerceJsonFuncExpr(pstate, expr, returning, false);
+
+	if (coercion->expr)
+	{
+		if (coercion->expr == expr)
+			coercion->expr = NULL;
+
+		return coercion;
+	}
+
+	typtype = get_typtype(returning->typid);
+
+	if (returning->typid == RECORDOID ||
+		typtype == TYPTYPE_COMPOSITE ||
+		typtype == TYPTYPE_DOMAIN ||
+		type_is_array(returning->typid))
+		coercion->via_populate = true;
+	else
+		coercion->via_io = true;
+
+	return coercion;
+}
+
+/*
+ * Transform a JSON output clause of JSON_VALUE and JSON_QUERY.
+ */
+static void
+transformJsonFuncExprOutput(ParseState *pstate,	JsonFuncExpr *func,
+							JsonExpr *jsexpr)
+{
+	Node	   *expr = jsexpr->formatted_expr;
+
+	jsexpr->returning = transformJsonOutput(pstate, func->output, false);
+
+	/* JSON_VALUE returns text by default */
+	if (func->op == IS_JSON_VALUE && !OidIsValid(jsexpr->returning->typid))
+	{
+		jsexpr->returning->typid = TEXTOID;
+		jsexpr->returning->typmod = -1;
+	}
+
+	if (OidIsValid(jsexpr->returning->typid))
+	{
+		JsonReturning ret;
+
+		if (func->op == IS_JSON_VALUE &&
+			jsexpr->returning->typid != JSONOID &&
+			jsexpr->returning->typid != JSONBOID)
+		{
+			/* Forced coercion via I/O for JSON_VALUE for non-JSON types */
+			jsexpr->result_coercion = makeNode(JsonCoercion);
+			jsexpr->result_coercion->expr = NULL;
+			jsexpr->result_coercion->via_io = true;
+			return;
+		}
+
+		assignDefaultJsonReturningType(jsexpr->formatted_expr, jsexpr->format, &ret);
+
+		if (ret.typid != jsexpr->returning->typid ||
+			ret.typmod != jsexpr->returning->typmod)
+		{
+			Node	   *placeholder = makeCaseTestExpr(expr);
+
+			Assert(((CaseTestExpr *) placeholder)->typeId == ret.typid);
+			Assert(((CaseTestExpr *) placeholder)->typeMod == ret.typmod);
+
+			jsexpr->result_coercion = coerceJsonExpr(pstate, placeholder,
+													 jsexpr->returning);
+		}
+	}
+	else
+		assignDefaultJsonReturningType(jsexpr->formatted_expr, jsexpr->format,
+									   jsexpr->returning);
+}
+
+/*
+ * Coerce a expression in JSON DEFAULT behavior to the target output type.
+ */
+static Node *
+coerceDefaultJsonExpr(ParseState *pstate, JsonExpr *jsexpr, Node *defexpr)
+{
+	int			location;
+	Oid			exprtype;
+
+	if (!defexpr)
+		return NULL;
+
+	exprtype = exprType(defexpr);
+	location = exprLocation(defexpr);
+
+	if (location < 0)
+		location = jsexpr->location;
+
+	defexpr = coerce_to_target_type(pstate,
+									defexpr,
+									exprtype,
+									jsexpr->returning->typid,
+									jsexpr->returning->typmod,
+									COERCION_EXPLICIT,
+									COERCE_IMPLICIT_CAST,
+									location);
+
+	if (!defexpr)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast DEFAULT expression type %s to %s",
+						format_type_be(exprtype),
+						format_type_be(jsexpr->returning->typid)),
+				 parser_errposition(pstate, location)));
+
+	return defexpr;
+}
+
+/*
+ * Initialize SQL/JSON item coercion from the SQL type "typid" to the target
+ * "returning" type.
+ */
+static JsonCoercion *
+initJsonItemCoercion(ParseState *pstate, Oid typid,
+					 const JsonReturning *returning)
+{
+	Node	   *expr;
+
+	if (typid == UNKNOWNOID)
+	{
+		expr = (Node *) makeNullConst(UNKNOWNOID, -1, InvalidOid);
+	}
+	else
+	{
+		CaseTestExpr *placeholder = makeNode(CaseTestExpr);
+
+		placeholder->typeId = typid;
+		placeholder->typeMod = -1;
+		placeholder->collation = InvalidOid;
+
+		expr = (Node *) placeholder;
+	}
+
+	return coerceJsonExpr(pstate, expr, returning);
+}
+
+static void
+initJsonItemCoercions(ParseState *pstate, JsonItemCoercions *coercions,
+					  const JsonReturning *returning, Oid contextItemTypeId)
+{
+	struct
+	{
+		JsonCoercion **coercion;
+		Oid			typid;
+	}		   *p,
+				coercionTypids[] =
+				{
+					{ &coercions->null, UNKNOWNOID },
+					{ &coercions->string, TEXTOID },
+					{ &coercions->numeric, NUMERICOID },
+					{ &coercions->boolean, BOOLOID },
+					{ &coercions->date, DATEOID },
+					{ &coercions->time, TIMEOID },
+					{ &coercions->timetz, TIMETZOID },
+					{ &coercions->timestamp, TIMESTAMPOID },
+					{ &coercions->timestamptz, TIMESTAMPTZOID },
+					{ &coercions->composite, contextItemTypeId },
+					{ NULL, InvalidOid }
+				};
+
+	for (p = coercionTypids; p->coercion; p++)
+		*p->coercion = initJsonItemCoercion(pstate, p->typid, returning);
+}
+
+/*
+ * Transform JSON_VALUE, JSON_QUERY, JSON_EXISTS functions into a JsonExpr node.
+ */
+static Node *
+transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *func)
+{
+	JsonExpr   *jsexpr = transformJsonExprCommon(pstate, func);
+	const char *func_name = NULL;
+	Node	   *contextItemExpr = jsexpr->formatted_expr;
+
+	switch (func->op)
+	{
+		case IS_JSON_VALUE:
+			func_name = "JSON_VALUE";
+
+			transformJsonFuncExprOutput(pstate, func, jsexpr);
+
+			jsexpr->returning->format->format = JS_FORMAT_DEFAULT;
+			jsexpr->returning->format->encoding = JS_ENC_DEFAULT;
+
+			jsexpr->on_empty->default_expr =
+				coerceDefaultJsonExpr(pstate, jsexpr,
+									  jsexpr->on_empty->default_expr);
+
+			jsexpr->on_error->default_expr =
+				coerceDefaultJsonExpr(pstate, jsexpr,
+									  jsexpr->on_error->default_expr);
+
+			jsexpr->coercions = makeNode(JsonItemCoercions);
+			initJsonItemCoercions(pstate, jsexpr->coercions, jsexpr->returning,
+								  exprType(contextItemExpr));
+
+			break;
+
+		case IS_JSON_QUERY:
+			func_name = "JSON_QUERY";
+
+			transformJsonFuncExprOutput(pstate, func, jsexpr);
+
+			jsexpr->on_empty->default_expr =
+				coerceDefaultJsonExpr(pstate, jsexpr,
+									  jsexpr->on_empty->default_expr);
+
+			jsexpr->on_error->default_expr =
+				coerceDefaultJsonExpr(pstate, jsexpr,
+									  jsexpr->on_error->default_expr);
+
+			jsexpr->wrapper = func->wrapper;
+			jsexpr->omit_quotes = func->omit_quotes;
+
+			break;
+
+		case IS_JSON_EXISTS:
+			func_name = "JSON_EXISTS";
+
+			jsexpr->returning = transformJsonOutput(pstate, func->output, false);
+
+			jsexpr->returning->format->format = JS_FORMAT_DEFAULT;
+			jsexpr->returning->format->encoding = JS_ENC_DEFAULT;
+
+			if (!OidIsValid(jsexpr->returning->typid))
+			{
+				jsexpr->returning->typid = BOOLOID;
+				jsexpr->returning->typmod = -1;
+			}
+			else if (jsexpr->returning->typid != BOOLOID)
+			{
+				CaseTestExpr *placeholder = makeNode(CaseTestExpr);
+				int			location = exprLocation((Node *) jsexpr);
+
+				placeholder->typeId = BOOLOID;
+				placeholder->typeMod = -1;
+				placeholder->collation = InvalidOid;
+
+				jsexpr->result_coercion = makeNode(JsonCoercion);
+				jsexpr->result_coercion->expr =
+					coerce_to_target_type(pstate, (Node *) placeholder, BOOLOID,
+										  jsexpr->returning->typid,
+										  jsexpr->returning->typmod,
+										  COERCION_EXPLICIT,
+										  COERCE_IMPLICIT_CAST,
+										  location);
+
+				if (!jsexpr->result_coercion->expr)
+					ereport(ERROR,
+							(errcode(ERRCODE_CANNOT_COERCE),
+							 errmsg("cannot cast type %s to %s",
+									format_type_be(BOOLOID),
+									format_type_be(jsexpr->returning->typid)),
+							 parser_coercion_errposition(pstate, location, (Node *) jsexpr)));
+
+				if (jsexpr->result_coercion->expr == (Node *) placeholder)
+					jsexpr->result_coercion->expr = NULL;
+			}
+			break;
+	}
+
+	if (exprType(contextItemExpr) != JSONBOID)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("%s() is not yet implemented for json type", func_name),
+				 parser_errposition(pstate, func->location)));
+
+	return (Node *) jsexpr;
+}
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index d4fa78862d..0159ba86ff 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1971,6 +1971,21 @@ FigureColnameInternal(Node *node, char **name)
 		case T_JsonArrayAgg:
 			*name = "json_arrayagg";
 			return 2;
+		case T_JsonFuncExpr:
+			/* make SQL/JSON functions act like a regular function */
+			switch (((JsonFuncExpr *) node)->op)
+			{
+				case IS_JSON_QUERY:
+					*name = "json_query";
+					return 2;
+				case IS_JSON_VALUE:
+					*name = "json_value";
+					return 2;
+				case IS_JSON_EXISTS:
+					*name = "json_exists";
+					return 2;
+			}
+			break;
 		default:
 			break;
 	}
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index a1145e2721..1f88f8d828 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -1018,11 +1018,6 @@ typedef struct NUMProc
 			   *L_currency_symbol;
 } NUMProc;
 
-/* Return flags for DCH_from_char() */
-#define DCH_DATED	0x01
-#define DCH_TIMED	0x02
-#define DCH_ZONED	0x04
-
 /* ----------
  * Functions
  * ----------
@@ -6673,3 +6668,43 @@ float8_to_char(PG_FUNCTION_ARGS)
 	NUM_TOCHAR_finish;
 	PG_RETURN_TEXT_P(result);
 }
+
+int
+datetime_format_flags(const char *fmt_str, bool *have_error)
+{
+	bool		incache;
+	int			fmt_len = strlen(fmt_str);
+	int			result;
+	FormatNode *format;
+
+	if (fmt_len > DCH_CACHE_SIZE)
+	{
+		/*
+		 * Allocate new memory if format picture is bigger than static cache
+		 * and do not use cache (call parser always)
+		 */
+		incache = false;
+
+		format = (FormatNode *) palloc((fmt_len + 1) * sizeof(FormatNode));
+
+		parse_format(format, fmt_str, DCH_keywords,
+					 DCH_suff, DCH_index, DCH_FLAG, NULL);
+	}
+	else
+	{
+		/*
+		 * Use cache buffers
+		 */
+		DCHCacheEntry *ent = DCH_cache_fetch(fmt_str, false);
+
+		incache = true;
+		format = ent->format;
+	}
+
+	result = DCH_datetime_type(format, have_error);
+
+	if (!incache)
+		pfree(format);
+
+	return result;
+}
diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 3d3e870408..a6650f6676 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -2227,3 +2227,65 @@ jsonb_float8(PG_FUNCTION_ARGS)
 
 	PG_RETURN_DATUM(retValue);
 }
+
+/*
+ * Construct an empty array jsonb.
+ */
+Jsonb *
+JsonbMakeEmptyArray(void)
+{
+	JsonbValue jbv;
+
+	jbv.type = jbvArray;
+	jbv.val.array.elems = NULL;
+	jbv.val.array.nElems = 0;
+	jbv.val.array.rawScalar = false;
+
+	return JsonbValueToJsonb(&jbv);
+}
+
+/*
+ * Construct an empty object jsonb.
+ */
+Jsonb *
+JsonbMakeEmptyObject(void)
+{
+	JsonbValue jbv;
+
+	jbv.type = jbvObject;
+	jbv.val.object.pairs = NULL;
+	jbv.val.object.nPairs = 0;
+
+	return JsonbValueToJsonb(&jbv);
+}
+
+/*
+ * Convert jsonb to a C-string stripping quotes from scalar strings.
+ */
+char *
+JsonbUnquote(Jsonb *jb)
+{
+	if (JB_ROOT_IS_SCALAR(jb))
+	{
+		JsonbValue	v;
+
+		JsonbExtractScalar(&jb->root, &v);
+
+		if (v.type == jbvString)
+			return pnstrdup(v.val.string.val, v.val.string.len);
+		else if (v.type == jbvBool)
+			return pstrdup(v.val.boolean ? "true" : "false");
+		else if (v.type == jbvNumeric)
+			return DatumGetCString(DirectFunctionCall1(numeric_out,
+									   PointerGetDatum(v.val.numeric)));
+		else if (v.type == jbvNull)
+			return pstrdup("null");
+		else
+		{
+			elog(ERROR, "unrecognized jsonb value type %d", v.type);
+			return NULL;
+		}
+	}
+	else
+		return JsonbToCString(NULL, &jb->root, VARSIZE(jb));
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 250c132066..7e1cb032f8 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -2771,11 +2771,11 @@ populate_array_dim_jsonb(PopulateArrayContext *ctx, /* context */
 
 	check_stack_depth();
 
-	if (jbv->type != jbvBinary || !JsonContainerIsArray(jbc))
+	if (jbv->type != jbvBinary ||
+		!JsonContainerIsArray(jbc) ||
+		JsonContainerIsScalar(jbc))
 		populate_array_report_expected_array(ctx, ndim - 1);
 
-	Assert(!JsonContainerIsScalar(jbc));
-
 	it = JsonbIteratorInit(jbc);
 
 	tok = JsonbIteratorNext(&it, &val, true);
@@ -3247,6 +3247,50 @@ populate_record_field(ColumnIOData *col,
 	}
 }
 
+/* recursively populate specified type from a json/jsonb value */
+Datum
+json_populate_type(Datum json_val, Oid json_type, Oid typid, int32 typmod,
+				   void **cache, MemoryContext mcxt, bool *isnull)
+{
+	JsValue		jsv = { 0 };
+	JsonbValue	jbv;
+
+	jsv.is_json = json_type == JSONOID;
+
+	if (*isnull)
+	{
+		if (jsv.is_json)
+			jsv.val.json.str = NULL;
+		else
+			jsv.val.jsonb = NULL;
+	}
+	else if (jsv.is_json)
+	{
+		text	   *json = DatumGetTextPP(json_val);
+
+		jsv.val.json.str = VARDATA_ANY(json);
+		jsv.val.json.len = VARSIZE_ANY_EXHDR(json);
+		jsv.val.json.type = JSON_TOKEN_INVALID; /* not used in populate_composite() */
+	}
+	else
+	{
+		Jsonb	   *jsonb = DatumGetJsonbP(json_val);
+
+		jsv.val.jsonb = &jbv;
+
+		/* fill binary jsonb value pointing to jb */
+		jbv.type = jbvBinary;
+		jbv.val.binary.data = &jsonb->root;
+		jbv.val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+	}
+
+	if (!*cache)
+		*cache = MemoryContextAllocZero(mcxt, sizeof(ColumnIOData));
+
+	return populate_record_field(*cache , typid, typmod, NULL, mcxt,
+								 PointerGetDatum(NULL), &jsv, isnull);
+}
+
 static RecordIOData *
 allocate_record_info(MemoryContext mcxt, int ncolumns)
 {
diff --git a/src/backend/utils/adt/jsonpath.c b/src/backend/utils/adt/jsonpath.c
index fa22546f22..43c9871506 100644
--- a/src/backend/utils/adt/jsonpath.c
+++ b/src/backend/utils/adt/jsonpath.c
@@ -67,7 +67,9 @@
 #include "lib/stringinfo.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
 #include "utils/builtins.h"
+#include "utils/formatting.h"
 #include "utils/json.h"
 #include "utils/jsonpath.h"
 
@@ -1073,3 +1075,258 @@ jspGetArraySubscript(JsonPathItem *v, JsonPathItem *from, JsonPathItem *to,
 
 	return true;
 }
+
+/* SQL/JSON datatype status: */
+typedef enum JsonPathDatatypeStatus
+{
+	jpdsNonDateTime,			/* null, bool, numeric, string, array, object */
+	jpdsUnknownDateTime,		/* unknown datetime type */
+	jpdsDateTimeZoned,			/* timetz, timestamptz */
+	jpdsDateTimeNonZoned		/* time, timestamp, date */
+} JsonPathDatatypeStatus;
+
+/* Context for jspIsMutableWalker() */
+typedef struct JsonPathMutableContext
+{
+	List	   *varnames;		/* list of variable names */
+	List	   *varexprs;		/* list of variable expressions */
+	JsonPathDatatypeStatus current;	/* status of @ item */
+	bool		lax;			/* jsonpath is lax or strict */
+	bool		mutable;		/* resulting mutability status */
+} JsonPathMutableContext;
+
+/*
+ * Recursive walker for jspIsMutable()
+ */
+static JsonPathDatatypeStatus
+jspIsMutableWalker(JsonPathItem *jpi, JsonPathMutableContext *cxt)
+{
+	JsonPathItem next;
+	JsonPathDatatypeStatus status = jpdsNonDateTime;
+
+	while (!cxt->mutable)
+	{
+		JsonPathItem arg;
+		JsonPathDatatypeStatus leftStatus;
+		JsonPathDatatypeStatus rightStatus;
+
+		switch (jpi->type)
+		{
+			case jpiRoot:
+				Assert(status == jpdsNonDateTime);
+				break;
+
+			case jpiCurrent:
+				Assert(status == jpdsNonDateTime);
+				status = cxt->current;
+				break;
+
+			case jpiFilter:
+				{
+					JsonPathDatatypeStatus prevStatus = cxt->current;
+
+					cxt->current = status;
+					jspGetArg(jpi, &arg);
+					jspIsMutableWalker(&arg, cxt);
+
+					cxt->current = prevStatus;
+					break;
+				}
+
+			case jpiVariable:
+				{
+					int32		len;
+					const char *name = jspGetString(jpi, &len);
+					ListCell   *lc1;
+					ListCell   *lc2;
+
+					Assert(status == jpdsNonDateTime);
+
+					forboth(lc1, cxt->varnames, lc2, cxt->varexprs)
+					{
+						String	   *varname = lfirst_node(String, lc1);
+						Node	   *varexpr = lfirst(lc2);
+
+						if (strncmp(varname->val, name, len))
+							continue;
+
+						switch (exprType(varexpr))
+						{
+							case DATEOID:
+							case TIMEOID:
+							case TIMESTAMPOID:
+								status = jpdsDateTimeNonZoned;
+								break;
+
+							case TIMETZOID:
+							case TIMESTAMPTZOID:
+								status = jpdsDateTimeZoned;
+								break;
+
+							default:
+								status = jpdsNonDateTime;
+								break;
+						}
+
+						break;
+					}
+					break;
+				}
+
+			case jpiEqual:
+			case jpiNotEqual:
+			case jpiLess:
+			case jpiGreater:
+			case jpiLessOrEqual:
+			case jpiGreaterOrEqual:
+				Assert(status == jpdsNonDateTime);
+				jspGetLeftArg(jpi, &arg);
+				leftStatus = jspIsMutableWalker(&arg, cxt);
+
+				jspGetRightArg(jpi, &arg);
+				rightStatus = jspIsMutableWalker(&arg, cxt);
+
+				/*
+				 * Comparison of datetime type with different timezone status
+				 * is mutable.
+				 */
+				if (leftStatus != jpdsNonDateTime &&
+					rightStatus != jpdsNonDateTime &&
+					(leftStatus == jpdsUnknownDateTime ||
+					 rightStatus == jpdsUnknownDateTime ||
+					 leftStatus != rightStatus))
+					cxt->mutable = true;
+				break;
+
+			case jpiNot:
+			case jpiIsUnknown:
+			case jpiExists:
+			case jpiPlus:
+			case jpiMinus:
+				Assert(status == jpdsNonDateTime);
+				jspGetArg(jpi, &arg);
+				jspIsMutableWalker(&arg, cxt);
+				break;
+
+			case jpiAnd:
+			case jpiOr:
+			case jpiAdd:
+			case jpiSub:
+			case jpiMul:
+			case jpiDiv:
+			case jpiMod:
+			case jpiStartsWith:
+				Assert(status == jpdsNonDateTime);
+				jspGetLeftArg(jpi, &arg);
+				jspIsMutableWalker(&arg, cxt);
+				jspGetRightArg(jpi, &arg);
+				jspIsMutableWalker(&arg, cxt);
+				break;
+
+			case jpiIndexArray:
+				for (int i = 0; i < jpi->content.array.nelems; i++)
+				{
+					JsonPathItem from;
+					JsonPathItem to;
+
+					if (jspGetArraySubscript(jpi, &from, &to, i))
+						jspIsMutableWalker(&to, cxt);
+
+					jspIsMutableWalker(&from, cxt);
+				}
+				/* FALLTHROUGH */
+
+			case jpiAnyArray:
+				if (!cxt->lax)
+					status = jpdsNonDateTime;
+				break;
+
+			case jpiAny:
+				if (jpi->content.anybounds.first > 0)
+					status = jpdsNonDateTime;
+				break;
+
+			case jpiDatetime:
+				if (jpi->content.arg)
+				{
+					char	   *template;
+					int			flags;
+
+					jspGetArg(jpi, &arg);
+					if (arg.type != jpiString)
+					{
+						status = jpdsNonDateTime;
+						break;	/* there will be runtime error */
+					}
+
+					template = jspGetString(&arg, NULL);
+					flags = datetime_format_flags(template, NULL);
+					if (flags & DCH_ZONED)
+						status = jpdsDateTimeZoned;
+					else
+						status = jpdsDateTimeNonZoned;
+				}
+				else
+				{
+					status = jpdsUnknownDateTime;
+				}
+				break;
+
+			case jpiLikeRegex:
+				Assert(status == jpdsNonDateTime);
+				jspInitByBuffer(&arg, jpi->base, jpi->content.like_regex.expr);
+				jspIsMutableWalker(&arg, cxt);
+				break;
+
+			/* literals */
+			case jpiNull:
+			case jpiString:
+			case jpiNumeric:
+			case jpiBool:
+			/* accessors */
+			case jpiKey:
+			case jpiAnyKey:
+			/* special items */
+			case jpiSubscript:
+			case jpiLast:
+			/* item methods */
+			case jpiType:
+			case jpiSize:
+			case jpiAbs:
+			case jpiFloor:
+			case jpiCeiling:
+			case jpiDouble:
+			case jpiKeyValue:
+				status = jpdsNonDateTime;
+				break;
+		}
+
+		if (!jspGetNext(jpi, &next))
+			break;
+
+		jpi = &next;
+	}
+
+	return status;
+}
+
+/*
+ * Check whether jsonpath expression is immutable or not.
+ */
+bool
+jspIsMutable(JsonPath *path, List *varnames, List *varexprs)
+{
+	JsonPathMutableContext cxt;
+	JsonPathItem jpi;
+
+	cxt.varnames = varnames;
+	cxt.varexprs = varexprs;
+	cxt.current = jpdsNonDateTime;
+	cxt.lax = (path->header & JSONPATH_LAX) != 0;
+	cxt.mutable = false;
+
+	jspInit(&jpi, path);
+	jspIsMutableWalker(&jpi, &cxt);
+
+	return cxt.mutable;
+}
diff --git a/src/backend/utils/adt/jsonpath_exec.c b/src/backend/utils/adt/jsonpath_exec.c
index 078aaef539..3b596be9fa 100644
--- a/src/backend/utils/adt/jsonpath_exec.c
+++ b/src/backend/utils/adt/jsonpath_exec.c
@@ -86,12 +86,16 @@ typedef struct JsonBaseObjectInfo
 	int			id;
 } JsonBaseObjectInfo;
 
+typedef int (*JsonPathVarCallback) (void *vars, char *varName, int varNameLen,
+									JsonbValue *val, JsonbValue *baseObject);
+
 /*
  * Context of jsonpath execution.
  */
 typedef struct JsonPathExecContext
 {
-	Jsonb	   *vars;			/* variables to substitute into jsonpath */
+	void	   *vars;			/* variables to substitute into jsonpath */
+	JsonPathVarCallback getVar;
 	JsonbValue *root;			/* for $ evaluation */
 	JsonbValue *current;		/* for @ evaluation */
 	JsonBaseObjectInfo baseObject;	/* "base object" for .keyvalue()
@@ -173,7 +177,8 @@ typedef JsonPathBool (*JsonPathPredicateCallback) (JsonPathItem *jsp,
 												   void *param);
 typedef Numeric (*BinaryArithmFunc) (Numeric num1, Numeric num2, bool *error);
 
-static JsonPathExecResult executeJsonPath(JsonPath *path, Jsonb *vars,
+static JsonPathExecResult executeJsonPath(JsonPath *path, void *vars,
+										  JsonPathVarCallback getVar,
 										  Jsonb *json, bool throwErrors,
 										  JsonValueList *result, bool useTz);
 static JsonPathExecResult executeItem(JsonPathExecContext *cxt,
@@ -225,7 +230,10 @@ static JsonPathExecResult appendBoolResult(JsonPathExecContext *cxt,
 static void getJsonPathItem(JsonPathExecContext *cxt, JsonPathItem *item,
 							JsonbValue *value);
 static void getJsonPathVariable(JsonPathExecContext *cxt,
-								JsonPathItem *variable, Jsonb *vars, JsonbValue *value);
+								JsonPathItem *variable, JsonbValue *value);
+static int getJsonPathVariableFromJsonb(void *varsJsonb, char *varName,
+										int varNameLen, JsonbValue *val,
+										JsonbValue *baseObject);
 static int	JsonbArraySize(JsonbValue *jb);
 static JsonPathBool executeComparison(JsonPathItem *cmp, JsonbValue *lv,
 									  JsonbValue *rv, void *p);
@@ -283,7 +291,8 @@ jsonb_path_exists_internal(FunctionCallInfo fcinfo, bool tz)
 		silent = PG_GETARG_BOOL(3);
 	}
 
-	res = executeJsonPath(jp, vars, jb, !silent, NULL, tz);
+	res = executeJsonPath(jp, vars, getJsonPathVariableFromJsonb,
+						  jb, !silent, NULL, tz);
 
 	PG_FREE_IF_COPY(jb, 0);
 	PG_FREE_IF_COPY(jp, 1);
@@ -338,7 +347,8 @@ jsonb_path_match_internal(FunctionCallInfo fcinfo, bool tz)
 		silent = PG_GETARG_BOOL(3);
 	}
 
-	(void) executeJsonPath(jp, vars, jb, !silent, &found, tz);
+	(void) executeJsonPath(jp, vars, getJsonPathVariableFromJsonb,
+						   jb, !silent, &found, tz);
 
 	PG_FREE_IF_COPY(jb, 0);
 	PG_FREE_IF_COPY(jp, 1);
@@ -416,7 +426,8 @@ jsonb_path_query_internal(FunctionCallInfo fcinfo, bool tz)
 		vars = PG_GETARG_JSONB_P_COPY(2);
 		silent = PG_GETARG_BOOL(3);
 
-		(void) executeJsonPath(jp, vars, jb, !silent, &found, tz);
+		(void) executeJsonPath(jp, vars, getJsonPathVariableFromJsonb,
+							   jb, !silent, &found, tz);
 
 		funcctx->user_fctx = JsonValueListGetList(&found);
 
@@ -463,7 +474,8 @@ jsonb_path_query_array_internal(FunctionCallInfo fcinfo, bool tz)
 	Jsonb	   *vars = PG_GETARG_JSONB_P(2);
 	bool		silent = PG_GETARG_BOOL(3);
 
-	(void) executeJsonPath(jp, vars, jb, !silent, &found, tz);
+	(void) executeJsonPath(jp, vars, getJsonPathVariableFromJsonb,
+						   jb, !silent, &found, tz);
 
 	PG_RETURN_JSONB_P(JsonbValueToJsonb(wrapItemsInArray(&found)));
 }
@@ -494,7 +506,8 @@ jsonb_path_query_first_internal(FunctionCallInfo fcinfo, bool tz)
 	Jsonb	   *vars = PG_GETARG_JSONB_P(2);
 	bool		silent = PG_GETARG_BOOL(3);
 
-	(void) executeJsonPath(jp, vars, jb, !silent, &found, tz);
+	(void) executeJsonPath(jp, vars, getJsonPathVariableFromJsonb,
+						   jb, !silent, &found, tz);
 
 	if (JsonValueListLength(&found) >= 1)
 		PG_RETURN_JSONB_P(JsonbValueToJsonb(JsonValueListHead(&found)));
@@ -536,8 +549,9 @@ jsonb_path_query_first_tz(PG_FUNCTION_ARGS)
  * In other case it tries to find all the satisfied result items.
  */
 static JsonPathExecResult
-executeJsonPath(JsonPath *path, Jsonb *vars, Jsonb *json, bool throwErrors,
-				JsonValueList *result, bool useTz)
+executeJsonPath(JsonPath *path, void *vars, JsonPathVarCallback getVar,
+				Jsonb *json, bool throwErrors, JsonValueList *result,
+				bool useTz)
 {
 	JsonPathExecContext cxt;
 	JsonPathExecResult res;
@@ -549,22 +563,16 @@ executeJsonPath(JsonPath *path, Jsonb *vars, Jsonb *json, bool throwErrors,
 	if (!JsonbExtractScalar(&json->root, &jbv))
 		JsonbInitBinary(&jbv, json);
 
-	if (vars && !JsonContainerIsObject(&vars->root))
-	{
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("\"vars\" argument is not an object"),
-				 errdetail("Jsonpath parameters should be encoded as key-value pairs of \"vars\" object.")));
-	}
-
 	cxt.vars = vars;
+	cxt.getVar = getVar;
 	cxt.laxMode = (path->header & JSONPATH_LAX) != 0;
 	cxt.ignoreStructuralErrors = cxt.laxMode;
 	cxt.root = &jbv;
 	cxt.current = &jbv;
 	cxt.baseObject.jbc = NULL;
 	cxt.baseObject.id = 0;
-	cxt.lastGeneratedObjectId = vars ? 2 : 1;
+	/* 1 + number of base objects in vars */
+	cxt.lastGeneratedObjectId = 1 + getVar(vars, NULL, 0, NULL, NULL);
 	cxt.innermostArraySize = -1;
 	cxt.throwErrors = throwErrors;
 	cxt.useTz = useTz;
@@ -2093,7 +2101,7 @@ getJsonPathItem(JsonPathExecContext *cxt, JsonPathItem *item,
 												 &value->val.string.len);
 			break;
 		case jpiVariable:
-			getJsonPathVariable(cxt, item, cxt->vars, value);
+			getJsonPathVariable(cxt, item, value);
 			return;
 		default:
 			elog(ERROR, "unexpected jsonpath item type");
@@ -2105,42 +2113,63 @@ getJsonPathItem(JsonPathExecContext *cxt, JsonPathItem *item,
  */
 static void
 getJsonPathVariable(JsonPathExecContext *cxt, JsonPathItem *variable,
-					Jsonb *vars, JsonbValue *value)
+					JsonbValue *value)
 {
 	char	   *varName;
 	int			varNameLength;
+	JsonbValue	baseObject;
+	int			baseObjectId;
+
+	Assert(variable->type == jpiVariable);
+	varName = jspGetString(variable, &varNameLength);
+
+	if (!cxt->vars ||
+		(baseObjectId = cxt->getVar(cxt->vars, varName, varNameLength, value,
+									&baseObject)) < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("could not find jsonpath variable \"%s\"",
+						pnstrdup(varName, varNameLength))));
+
+	if (baseObjectId > 0)
+		setBaseObject(cxt, &baseObject, baseObjectId);
+}
+
+static int
+getJsonPathVariableFromJsonb(void *varsJsonb, char *varName, int varNameLength,
+							 JsonbValue *value, JsonbValue *baseObject)
+{
+	Jsonb	   *vars = varsJsonb;
 	JsonbValue	tmp;
 	JsonbValue *v;
 
-	if (!vars)
+	if (!varName)
 	{
-		value->type = jbvNull;
-		return;
+		if (vars && !JsonContainerIsObject(&vars->root))
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("\"vars\" argument is not an object"),
+					 errdetail("Jsonpath parameters should be encoded as key-value pairs of \"vars\" object.")));
+		}
+
+		return vars ? 1 : 0;	/* count of base objects */
 	}
 
-	Assert(variable->type == jpiVariable);
-	varName = jspGetString(variable, &varNameLength);
 	tmp.type = jbvString;
 	tmp.val.string.val = varName;
 	tmp.val.string.len = varNameLength;
 
 	v = findJsonbValueFromContainer(&vars->root, JB_FOBJECT, &tmp);
 
-	if (v)
-	{
-		*value = *v;
-		pfree(v);
-	}
-	else
-	{
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("could not find jsonpath variable \"%s\"",
-						pnstrdup(varName, varNameLength))));
-	}
+	if (!v)
+		return -1;
 
-	JsonbInitBinary(&tmp, vars);
-	setBaseObject(cxt, &tmp, 1);
+	*value = *v;
+	pfree(v);
+
+	JsonbInitBinary(baseObject, vars);
+	return 1;
 }
 
 /**************** Support functions for JsonPath execution *****************/
@@ -2797,3 +2826,244 @@ compareDatetime(Datum val1, Oid typid1, Datum val2, Oid typid2,
 
 	return DatumGetInt32(DirectFunctionCall2(cmpfunc, val1, val2));
 }
+
+/********************Interface to pgsql's executor***************************/
+
+bool
+JsonPathExists(Datum jb, JsonPath *jp, List *vars, bool *error)
+{
+	JsonPathExecResult res = executeJsonPath(jp, vars, EvalJsonPathVar,
+											 DatumGetJsonbP(jb), !error, NULL,
+											 true);
+
+	Assert(error || !jperIsError(res));
+
+	if (error && jperIsError(res))
+		*error = true;
+
+	return res == jperOk;
+}
+
+Datum
+JsonPathQuery(Datum jb, JsonPath *jp, JsonWrapper wrapper, bool *empty,
+			  bool *error, List *vars)
+{
+	JsonbValue *first;
+	bool		wrap;
+	JsonValueList found = {0};
+	JsonPathExecResult res PG_USED_FOR_ASSERTS_ONLY;
+	int			count;
+
+	res = executeJsonPath(jp, vars, EvalJsonPathVar, DatumGetJsonbP(jb), !error,
+						  &found, true);
+
+	Assert(error || !jperIsError(res));
+
+	if (error && jperIsError(res))
+	{
+		*error = true;
+		*empty = false;
+		return (Datum) 0;
+	}
+
+	count = JsonValueListLength(&found);
+
+	first = count ? JsonValueListHead(&found) : NULL;
+
+	if (!first)
+		wrap = false;
+	else if (wrapper == JSW_NONE)
+		wrap = false;
+	else if (wrapper == JSW_UNCONDITIONAL)
+		wrap = true;
+	else if (wrapper == JSW_CONDITIONAL)
+		wrap = count > 1 ||
+			IsAJsonbScalar(first) ||
+			(first->type == jbvBinary &&
+			 JsonContainerIsScalar(first->val.binary.data));
+	else
+	{
+		elog(ERROR, "unrecognized json wrapper %d", wrapper);
+		wrap = false;
+	}
+
+	if (wrap)
+		return JsonbPGetDatum(JsonbValueToJsonb(wrapItemsInArray(&found)));
+
+	if (count > 1)
+	{
+		if (error)
+		{
+			*error = true;
+			return (Datum) 0;
+		}
+
+		ereport(ERROR,
+				(errcode(ERRCODE_MORE_THAN_ONE_SQL_JSON_ITEM),
+				 errmsg("JSON path expression in JSON_QUERY should return "
+						"singleton item without wrapper"),
+				 errhint("use WITH WRAPPER clause to wrap SQL/JSON item "
+						 "sequence into array")));
+	}
+
+	if (first)
+		return JsonbPGetDatum(JsonbValueToJsonb(first));
+
+	*empty = true;
+	return PointerGetDatum(NULL);
+}
+
+JsonbValue *
+JsonPathValue(Datum jb, JsonPath *jp, bool *empty, bool *error, List *vars)
+{
+	JsonbValue   *res;
+	JsonValueList found = { 0 };
+	JsonPathExecResult jper PG_USED_FOR_ASSERTS_ONLY;
+	int			count;
+
+	jper = executeJsonPath(jp, vars, EvalJsonPathVar, DatumGetJsonbP(jb), !error,
+						   &found, true);
+
+	Assert(error || !jperIsError(jper));
+
+	if (error && jperIsError(jper))
+	{
+		*error = true;
+		*empty = false;
+		return NULL;
+	}
+
+	count = JsonValueListLength(&found);
+
+	*empty = !count;
+
+	if (*empty)
+		return NULL;
+
+	if (count > 1)
+	{
+		if (error)
+		{
+			*error = true;
+			return NULL;
+		}
+
+		ereport(ERROR,
+				(errcode(ERRCODE_MORE_THAN_ONE_SQL_JSON_ITEM),
+				 errmsg("JSON path expression in JSON_VALUE should return "
+						"singleton scalar item")));
+	}
+
+	res = JsonValueListHead(&found);
+
+	if (res->type == jbvBinary &&
+		JsonContainerIsScalar(res->val.binary.data))
+		JsonbExtractScalar(res->val.binary.data, res);
+
+	if (!IsAJsonbScalar(res))
+	{
+		if (error)
+		{
+			*error = true;
+			return NULL;
+		}
+
+		ereport(ERROR,
+				(errcode(ERRCODE_SQL_JSON_SCALAR_REQUIRED),
+				 errmsg("JSON path expression in JSON_VALUE should return "
+						"singleton scalar item")));
+	}
+
+	if (res->type == jbvNull)
+		return NULL;
+
+	return res;
+}
+
+static void
+JsonbValueInitNumericDatum(JsonbValue *jbv, Datum num)
+{
+	jbv->type = jbvNumeric;
+	jbv->val.numeric = DatumGetNumeric(num);
+}
+
+void
+JsonItemFromDatum(Datum val, Oid typid, int32 typmod, JsonbValue *res)
+{
+	switch (typid)
+	{
+		case BOOLOID:
+			res->type = jbvBool;
+			res->val.boolean = DatumGetBool(val);
+			break;
+		case NUMERICOID:
+			JsonbValueInitNumericDatum(res, val);
+			break;
+		case INT2OID:
+			JsonbValueInitNumericDatum(res, DirectFunctionCall1(int2_numeric, val));
+			break;
+		case INT4OID:
+			JsonbValueInitNumericDatum(res, DirectFunctionCall1(int4_numeric, val));
+			break;
+		case INT8OID:
+			JsonbValueInitNumericDatum(res, DirectFunctionCall1(int8_numeric, val));
+			break;
+		case FLOAT4OID:
+			JsonbValueInitNumericDatum(res, DirectFunctionCall1(float4_numeric, val));
+			break;
+		case FLOAT8OID:
+			JsonbValueInitNumericDatum(res, DirectFunctionCall1(float8_numeric, val));
+			break;
+		case TEXTOID:
+		case VARCHAROID:
+			res->type = jbvString;
+			res->val.string.val = VARDATA_ANY(val);
+			res->val.string.len = VARSIZE_ANY_EXHDR(val);
+			break;
+		case DATEOID:
+		case TIMEOID:
+		case TIMETZOID:
+		case TIMESTAMPOID:
+		case TIMESTAMPTZOID:
+			res->type = jbvDatetime;
+			res->val.datetime.value = val;
+			res->val.datetime.typid = typid;
+			res->val.datetime.typmod = typmod;
+			res->val.datetime.tz = 0;
+			break;
+		case JSONBOID:
+			{
+				JsonbValue *jbv = res;
+				Jsonb	   *jb = DatumGetJsonbP(val);
+
+				if (JsonContainerIsScalar(&jb->root))
+				{
+					bool		res PG_USED_FOR_ASSERTS_ONLY;
+
+					res = JsonbExtractScalar(&jb->root, jbv);
+					Assert(res);
+				}
+				else
+					JsonbInitBinary(jbv, jb);
+				break;
+			}
+		case JSONOID:
+			{
+				text	   *txt = DatumGetTextP(val);
+				char	   *str = text_to_cstring(txt);
+				Jsonb	   *jb =
+					DatumGetJsonbP(DirectFunctionCall1(jsonb_in,
+													   CStringGetDatum(str)));
+
+				pfree(str);
+
+				JsonItemFromDatum(JsonbPGetDatum(jb), JSONBOID, -1, res);
+				break;
+			}
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("only bool, numeric and text types could be "
+							"casted to supported jsonpath types.")));
+	}
+}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index de430f8cca..4faa8f59b6 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -492,6 +492,8 @@ static char *generate_qualified_type_name(Oid typid);
 static text *string_to_text(char *str);
 static char *flatten_reloptions(Oid relid);
 static void get_reloptions(StringInfo buf, Datum reloptions);
+static void get_json_path_spec(Node *path_spec, deparse_context *context,
+							   bool showimplicit);
 
 #define only_marker(rte)  ((rte)->inh ? "" : "ONLY ")
 
@@ -8000,6 +8002,7 @@ isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
 		case T_WindowFunc:
 		case T_FuncExpr:
 		case T_JsonConstructorExpr:
+		case T_JsonExpr:
 			/* function-like: name(..) or name[..] */
 			return true;
 
@@ -8117,6 +8120,7 @@ isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
 				case T_Aggref:	/* own parentheses */
 				case T_WindowFunc:	/* own parentheses */
 				case T_CaseExpr:	/* other separators */
+				case T_JsonExpr: /* own parentheses */
 					return true;
 				default:
 					return false;
@@ -8282,6 +8286,19 @@ get_rule_expr_paren(Node *node, deparse_context *context,
 		appendStringInfoChar(context->buf, ')');
 }
 
+
+/*
+ * get_json_path_spec		- Parse back a JSON path specification
+ */
+static void
+get_json_path_spec(Node *path_spec, deparse_context *context, bool showimplicit)
+{
+	if (IsA(path_spec, Const))
+		get_const_expr((Const *) path_spec, context, -1);
+	else
+		get_rule_expr(path_spec, context, showimplicit);
+}
+
 /*
  * get_json_format			- Parse back a JsonFormat node
  */
@@ -8325,6 +8342,66 @@ get_json_returning(JsonReturning *returning, StringInfo buf,
 		get_json_format(returning->format, buf);
 }
 
+static void
+get_json_behavior(JsonBehavior *behavior, deparse_context *context,
+				  const char *on)
+{
+	/*
+	 * The order of array elements must correspond to the order of
+	 * JsonBehaviorType members.
+	 */
+	const char *behavior_names[] =
+	{
+		" NULL",
+		" ERROR",
+		" EMPTY",
+		" TRUE",
+		" FALSE",
+		" UNKNOWN",
+		" EMPTY ARRAY",
+		" EMPTY OBJECT",
+		" DEFAULT "
+	};
+
+	if ((int) behavior->btype < 0 || behavior->btype >= lengthof(behavior_names))
+		elog(ERROR, "invalid json behavior type: %d", behavior->btype);
+
+	appendStringInfoString(context->buf, behavior_names[behavior->btype]);
+
+	if (behavior->btype == JSON_BEHAVIOR_DEFAULT)
+		get_rule_expr(behavior->default_expr, context, false);
+
+	appendStringInfo(context->buf, " ON %s", on);
+}
+
+/*
+ * get_json_expr_options
+ *
+ * Parse back common options for JSON_QUERY, JSON_VALUE, JSON_EXISTS.
+ */
+static void
+get_json_expr_options(JsonExpr *jsexpr, deparse_context *context,
+					  JsonBehaviorType default_behavior)
+{
+	if (jsexpr->op == IS_JSON_QUERY)
+	{
+		if (jsexpr->wrapper == JSW_CONDITIONAL)
+			appendStringInfo(context->buf, " WITH CONDITIONAL WRAPPER");
+		else if (jsexpr->wrapper == JSW_UNCONDITIONAL)
+			appendStringInfo(context->buf, " WITH UNCONDITIONAL WRAPPER");
+
+		if (jsexpr->omit_quotes)
+			appendStringInfo(context->buf, " OMIT QUOTES");
+	}
+
+	if (jsexpr->op != IS_JSON_EXISTS &&
+		jsexpr->on_empty->btype != default_behavior)
+		get_json_behavior(jsexpr->on_empty, context, "EMPTY");
+
+	if (jsexpr->on_error->btype != default_behavior)
+		get_json_behavior(jsexpr->on_error, context, "ERROR");
+}
+
 /* ----------
  * get_rule_expr			- Parse back an expression
  *
@@ -9500,6 +9577,7 @@ get_rule_expr(Node *node, deparse_context *context,
 			}
 			break;
 
+
 		case T_JsonValueExpr:
 			{
 				JsonValueExpr *jve = (JsonValueExpr *) node;
@@ -9547,6 +9625,62 @@ get_rule_expr(Node *node, deparse_context *context,
 			}
 			break;
 
+		case T_JsonExpr:
+			{
+				JsonExpr   *jexpr = (JsonExpr *) node;
+
+				switch (jexpr->op)
+				{
+					case IS_JSON_QUERY:
+						appendStringInfoString(buf, "JSON_QUERY(");
+						break;
+					case IS_JSON_VALUE:
+						appendStringInfoString(buf, "JSON_VALUE(");
+						break;
+					case IS_JSON_EXISTS:
+						appendStringInfoString(buf, "JSON_EXISTS(");
+						break;
+				}
+
+				get_rule_expr(jexpr->formatted_expr, context, showimplicit);
+
+				appendStringInfoString(buf, ", ");
+
+				get_json_path_spec(jexpr->path_spec, context, showimplicit);
+
+				if (jexpr->passing_values)
+				{
+					ListCell   *lc1, *lc2;
+					bool		needcomma = false;
+
+					appendStringInfoString(buf, " PASSING ");
+
+					forboth(lc1, jexpr->passing_names,
+							lc2, jexpr->passing_values)
+					{
+						if (needcomma)
+							appendStringInfoString(buf, ", ");
+						needcomma = true;
+
+						get_rule_expr((Node *) lfirst(lc2), context, showimplicit);
+						appendStringInfo(buf, " AS %s",
+										 ((String *) lfirst_node(String, lc1))->val);
+					}
+				}
+
+				if (jexpr->op != IS_JSON_EXISTS ||
+					jexpr->returning->typid != BOOLOID)
+					get_json_returning(jexpr->returning, context->buf,
+									   jexpr->op == IS_JSON_QUERY);
+
+				get_json_expr_options(jexpr, context,
+									  jexpr->op == IS_JSON_EXISTS ?
+									  JSON_BEHAVIOR_FALSE : JSON_BEHAVIOR_NULL);
+
+				appendStringInfoString(buf, ")");
+			}
+			break;
+
 		case T_List:
 			{
 				char	   *sep;
@@ -9644,6 +9778,7 @@ looks_like_function(Node *node)
 		case T_MinMaxExpr:
 		case T_SQLValueFunction:
 		case T_XmlExpr:
+		case T_JsonExpr:
 			/* these are all accepted by func_expr_common_subexpr */
 			return true;
 		default:
diff --git a/src/backend/utils/misc/queryjumble.c b/src/backend/utils/misc/queryjumble.c
index 5b1c10a09c..9b1252f06d 100644
--- a/src/backend/utils/misc/queryjumble.c
+++ b/src/backend/utils/misc/queryjumble.c
@@ -785,6 +785,27 @@ JumbleExpr(JumbleState *jstate, Node *node)
 				APP_JUMB(pred->value_type);
 			}
 			break;
+		case T_JsonExpr:
+			{
+				JsonExpr    *jexpr = (JsonExpr *) node;
+
+				APP_JUMB(jexpr->op);
+				JumbleExpr(jstate, jexpr->formatted_expr);
+				JumbleExpr(jstate, jexpr->path_spec);
+				foreach(temp, jexpr->passing_names)
+				{
+					APP_JUMB_STRING(lfirst_node(String, temp)->val);
+				}
+				JumbleExpr(jstate, (Node *) jexpr->passing_values);
+				if (jexpr->on_empty)
+				{
+					APP_JUMB(jexpr->on_empty->btype);
+					JumbleExpr(jstate, jexpr->on_empty->default_expr);
+				}
+				APP_JUMB(jexpr->on_error->btype);
+				JumbleExpr(jstate, jexpr->on_error->default_expr);
+			}
+			break;
 		case T_List:
 			foreach(temp, (List *) node)
 			{
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index 715fadb649..1e32fbb748 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -21,6 +21,7 @@
 struct ExprEvalStep;
 struct SubscriptingRefState;
 struct ScalarArrayOpExprHashTable;
+struct JsonbValue;
 
 /* Bits in ExprState->flags (see also execnodes.h for public flag bits): */
 /* expression's interpreter has been initialized */
@@ -241,6 +242,7 @@ typedef enum ExprEvalOp
 	EEOP_SUBPLAN,
 	EEOP_JSON_CONSTRUCTOR,
 	EEOP_IS_JSON,
+	EEOP_JSONEXPR,
 
 	/* aggregation related nodes */
 	EEOP_AGG_STRICT_DESERIALIZE,
@@ -687,6 +689,50 @@ typedef struct ExprEvalStep
 					JsonIsPredicate *pred;	/* original expression node */
 		}			is_json;
 
+		/* for EEOP_JSONEXPR */
+		struct
+		{
+			JsonExpr   *jsexpr;			/* original expression node */
+
+			struct
+			{
+				FmgrInfo	func;		/* typinput function for output type */
+				Oid			typioparam;
+			} input;					/* I/O info for output type */
+
+			NullableDatum
+					   *formatted_expr,		/* formatted context item value */
+					   *res_expr,			/* result item */
+					   *coercion_expr,		/* input for JSON item coercion */
+					   *pathspec;			/* path specification value */
+
+			ExprState  *result_expr;		/* coerced to output type */
+			ExprState  *default_on_empty;	/* ON EMPTY DEFAULT expression */
+			ExprState  *default_on_error;	/* ON ERROR DEFAULT expression */
+			List	   *args;				/* passing arguments */
+
+			void	   *cache;				/* cache for json_populate_type() */
+
+			struct JsonCoercionsState
+			{
+				struct JsonCoercionState
+				{
+					JsonCoercion *coercion;		/* coercion expression */
+					ExprState  *estate;	/* coercion expression state */
+				} 			null,
+							string,
+							numeric,
+							boolean,
+							date,
+							time,
+							timetz,
+							timestamp,
+							timestamptz,
+							composite;
+			}			coercions;	/* states for coercion from SQL/JSON item
+									 * types directly to the output type */
+		}			jsonexpr;
+
 	}			d;
 } ExprEvalStep;
 
@@ -791,6 +837,14 @@ extern void ExecEvalSysVar(ExprState *state, ExprEvalStep *op,
 						   ExprContext *econtext, TupleTableSlot *slot);
 extern void ExecEvalJsonConstructor(ExprState *state, ExprEvalStep *op,
 									ExprContext *econtext);
+extern void ExecEvalJson(ExprState *state, ExprEvalStep *op,
+						 ExprContext *econtext);
+extern Datum ExecPrepareJsonItemCoercion(struct JsonbValue *item,
+										 JsonReturning *returning,
+										 struct JsonCoercionsState *coercions,
+										 struct JsonCoercionState **pjcstate);
+extern bool ExecEvalJsonNeedsSubTransaction(JsonExpr *jsexpr,
+											struct JsonCoercionsState *);
 
 extern void ExecAggInitGroup(AggState *aggstate, AggStatePerTrans pertrans, AggStatePerGroup pergroup,
 							 ExprContext *aggcontext);
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index cd57a704ad..26a4bd28ee 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -263,6 +263,8 @@ ExecProcNode(PlanState *node)
  */
 extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
 extern ExprState *ExecInitExprWithParams(Expr *node, ParamListInfo ext_params);
+extern ExprState *ExecInitExprWithCaseValue(Expr *node, PlanState *parent,
+						  Datum *caseval, bool *casenull);
 extern ExprState *ExecInitQual(List *qual, PlanState *parent);
 extern ExprState *ExecInitCheck(List *qual, PlanState *parent);
 extern List *ExecInitExprList(List *nodes, PlanState *parent);
diff --git a/src/include/nodes/makefuncs.h b/src/include/nodes/makefuncs.h
index 9e1737337c..c1cfbfc6b3 100644
--- a/src/include/nodes/makefuncs.h
+++ b/src/include/nodes/makefuncs.h
@@ -109,6 +109,7 @@ extern VacuumRelation *makeVacuumRelation(RangeVar *relation, Oid oid, List *va_
 extern JsonFormat *makeJsonFormat(JsonFormatType type, JsonEncoding encoding,
 								  int location);
 extern JsonValueExpr *makeJsonValueExpr(Expr *expr, JsonFormat *format);
+extern JsonBehavior *makeJsonBehavior(JsonBehaviorType type, Node *expr);
 extern Node *makeJsonKeyValue(Node *key, Node *value);
 extern Node *makeJsonIsPredicate(Node *expr, JsonFormat *format,
 								 JsonValueType vtype, bool unique_keys,
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index ddec930ae8..6de59c25d7 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -205,6 +205,9 @@ typedef enum NodeTag
 	T_JsonReturning,
 	T_JsonValueExpr,
 	T_JsonConstructorExpr,
+	T_JsonExpr,
+	T_JsonCoercion,
+	T_JsonItemCoercions,
 
 	/*
 	 * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
@@ -498,8 +501,13 @@ typedef enum NodeTag
 	T_JsonAggConstructor,
 	T_JsonObjectAgg,
 	T_JsonArrayAgg,
+	T_JsonFuncExpr,
 	T_JsonIsPredicate,
+	T_JsonExistsPredicate,
+	T_JsonCommon,
+	T_JsonArgument,
 	T_JsonKeyValue,
+	T_JsonBehavior,
 	T_JsonOutput,
 
 	/*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 4b00963fe9..aad7f2f650 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1552,6 +1552,23 @@ typedef struct TriggerTransition
 
 /* Nodes for SQL/JSON support */
 
+/*
+ * JsonQuotes -
+ *		representation of [KEEP|OMIT] QUOTES clause for JSON_QUERY()
+ */
+typedef enum JsonQuotes
+{
+	JS_QUOTES_UNSPEC,			/* unspecified */
+	JS_QUOTES_KEEP,				/* KEEP QUOTES */
+	JS_QUOTES_OMIT				/* OMIT QUOTES */
+} JsonQuotes;
+
+/*
+ * JsonPathSpec -
+ *		representation of JSON path constant
+ */
+typedef char *JsonPathSpec;
+
 /*
  * JsonOutput -
  *		representation of JSON output clause (RETURNING type [FORMAT format])
@@ -1563,6 +1580,48 @@ typedef struct JsonOutput
 	JsonReturning *returning;	/* RETURNING FORMAT clause and type Oids */
 } JsonOutput;
 
+/*
+ * JsonArgument -
+ *		representation of argument from JSON PASSING clause
+ */
+typedef struct JsonArgument
+{
+	NodeTag		type;
+	JsonValueExpr *val;			/* argument value expression */
+	char	   *name;			/* argument name */
+} JsonArgument;
+
+/*
+ * JsonCommon -
+ *		representation of common syntax of functions using JSON path
+ */
+typedef struct JsonCommon
+{
+	NodeTag		type;
+	JsonValueExpr *expr;		/* context item expression */
+	Node	   *pathspec;		/* JSON path specification expression */
+	char	   *pathname;		/* path name, if any */
+	List	   *passing;		/* list of PASSING clause arguments, if any */
+	int			location;		/* token location, or -1 if unknown */
+} JsonCommon;
+
+/*
+ * JsonFuncExpr -
+ *		untransformed representation of JSON function expressions
+ */
+typedef struct JsonFuncExpr
+{
+	NodeTag		type;
+	JsonExprOp	op;				/* expression type */
+	JsonCommon *common;			/* common syntax */
+	JsonOutput *output;			/* output clause, if specified */
+	JsonBehavior *on_empty;		/* ON EMPTY behavior, if specified */
+	JsonBehavior *on_error;		/* ON ERROR behavior, if specified */
+	JsonWrapper	wrapper;		/* array wrapper behavior (JSON_QUERY only) */
+	bool		omit_quotes;	/* omit or keep quotes? (JSON_QUERY only) */
+	int			location;		/* token location, or -1 if unknown */
+} JsonFuncExpr;
+
 /*
  * JsonKeyValue -
  *		untransformed representation of JSON object key-value pair for
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 58f3d98698..336597b67c 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1235,6 +1235,17 @@ typedef struct XmlExpr
 	int			location;		/* token location, or -1 if unknown */
 } XmlExpr;
 
+/*
+ * JsonExprOp -
+ *		enumeration of JSON functions using JSON path
+ */
+typedef enum JsonExprOp
+{
+	IS_JSON_VALUE,				/* JSON_VALUE() */
+	IS_JSON_QUERY,				/* JSON_QUERY() */
+	IS_JSON_EXISTS				/* JSON_EXISTS() */
+} JsonExprOp;
+
 /*
  * JsonEncoding -
  *		representation of JSON ENCODING clause
@@ -1258,6 +1269,37 @@ typedef enum JsonFormatType
 	JS_FORMAT_JSONB				/* implicit internal format for RETURNING jsonb */
 } JsonFormatType;
 
+/*
+ * JsonBehaviorType -
+ *		enumeration of behavior types used in JSON ON ... BEHAVIOR clause
+ *
+ * 		If enum members are reordered, get_json_behavior() from ruleutils.c
+ * 		must be updated accordingly.
+ */
+typedef enum JsonBehaviorType
+{
+	JSON_BEHAVIOR_NULL = 0,
+	JSON_BEHAVIOR_ERROR,
+	JSON_BEHAVIOR_EMPTY,
+	JSON_BEHAVIOR_TRUE,
+	JSON_BEHAVIOR_FALSE,
+	JSON_BEHAVIOR_UNKNOWN,
+	JSON_BEHAVIOR_EMPTY_ARRAY,
+	JSON_BEHAVIOR_EMPTY_OBJECT,
+	JSON_BEHAVIOR_DEFAULT
+} JsonBehaviorType;
+
+/*
+ * JsonWrapper -
+ *		representation of WRAPPER clause for JSON_QUERY()
+ */
+typedef enum JsonWrapper
+{
+	JSW_NONE,
+	JSW_CONDITIONAL,
+	JSW_UNCONDITIONAL,
+} JsonWrapper;
+
 /*
  * JsonFormat -
  *		representation of JSON FORMAT clause
@@ -1345,6 +1387,73 @@ typedef struct JsonIsPredicate
 	int			location;		/* token location, or -1 if unknown */
 } JsonIsPredicate;
 
+/*
+ * JsonBehavior -
+ *		representation of JSON ON ... BEHAVIOR clause
+ */
+typedef struct JsonBehavior
+{
+	NodeTag		type;
+	JsonBehaviorType btype;		/* behavior type */
+	Node	   *default_expr;	/* default expression, if any */
+} JsonBehavior;
+
+/*
+ * JsonCoercion -
+ *		coercion from SQL/JSON item types to SQL types
+ */
+typedef struct JsonCoercion
+{
+	NodeTag		type;
+	Node	   *expr;			/* resulting expression coerced to target type */
+	bool		via_populate;	/* coerce result using json_populate_type()? */
+	bool		via_io;			/* coerce result using type input function? */
+	Oid			collation;		/* collation for coercion via I/O or populate */
+} JsonCoercion;
+
+/*
+ * JsonItemCoercions -
+ *		expressions for coercion from SQL/JSON item types directly to the
+ *		output SQL type
+ */
+typedef struct JsonItemCoercions
+{
+	NodeTag		type;
+	JsonCoercion *null;
+	JsonCoercion *string;
+	JsonCoercion *numeric;
+	JsonCoercion *boolean;
+	JsonCoercion *date;
+	JsonCoercion *time;
+	JsonCoercion *timetz;
+	JsonCoercion *timestamp;
+	JsonCoercion *timestamptz;
+	JsonCoercion *composite;	/* arrays and objects */
+} JsonItemCoercions;
+
+/*
+ * JsonExpr -
+ *		transformed representation of JSON_VALUE(), JSON_QUERY(), JSON_EXISTS()
+ */
+typedef struct JsonExpr
+{
+	Expr		xpr;
+	JsonExprOp	op;				/* json function ID */
+	Node	   *formatted_expr;	/* formatted context item expression */
+	JsonCoercion *result_coercion;	/* resulting coercion to RETURNING type */
+	JsonFormat *format;			/* context item format (JSON/JSONB) */
+	Node	   *path_spec;		/* JSON path specification expression */
+	List	   *passing_names;	/* PASSING argument names */
+	List	   *passing_values;	/* PASSING argument values */
+	JsonReturning *returning;	/* RETURNING clause type/format info */
+	JsonBehavior *on_empty;		/* ON EMPTY behavior */
+	JsonBehavior *on_error;		/* ON ERROR behavior */
+	JsonItemCoercions *coercions; /* coercions for JSON_VALUE */
+	JsonWrapper	wrapper;		/* WRAPPER for JSON_QUERY */
+	bool		omit_quotes;	/* KEEP/OMIT QUOTES for JSON_QUERY */
+	int			location;		/* token location, or -1 if unknown */
+} JsonExpr;
+
 /* ----------------
  * NullTest
  *
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 2d37a8b063..fd0be1b526 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -93,6 +93,7 @@ PG_KEYWORD("commit", COMMIT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("committed", COMMITTED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("compression", COMPRESSION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("concurrently", CONCURRENTLY, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("conditional", CONDITIONAL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("configuration", CONFIGURATION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("conflict", CONFLICT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("connection", CONNECTION, UNRESERVED_KEYWORD, BARE_LABEL)
@@ -147,11 +148,13 @@ PG_KEYWORD("double", DOUBLE_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("drop", DROP, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("each", EACH, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("else", ELSE, RESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("empty", EMPTY_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("enable", ENABLE_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("encoding", ENCODING, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("encrypted", ENCRYPTED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("end", END_P, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("enum", ENUM_P, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("error", ERROR_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("escape", ESCAPE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("event", EVENT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("except", EXCEPT, RESERVED_KEYWORD, AS_LABEL)
@@ -232,8 +235,12 @@ PG_KEYWORD("join", JOIN, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("json", JSON, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("json_array", JSON_ARRAY, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("json_arrayagg", JSON_ARRAYAGG, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("json_exists", JSON_EXISTS, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("json_object", JSON_OBJECT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("json_objectagg", JSON_OBJECTAGG, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("json_query", JSON_QUERY, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("json_value", JSON_VALUE, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("keep", KEEP, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("key", KEY, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("keys", KEYS, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("label", LABEL, UNRESERVED_KEYWORD, BARE_LABEL)
@@ -297,6 +304,7 @@ PG_KEYWORD("off", OFF, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("offset", OFFSET, RESERVED_KEYWORD, AS_LABEL)
 PG_KEYWORD("oids", OIDS, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("old", OLD, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("omit", OMIT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("on", ON, RESERVED_KEYWORD, AS_LABEL)
 PG_KEYWORD("only", ONLY, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("operator", OPERATOR, UNRESERVED_KEYWORD, BARE_LABEL)
@@ -338,6 +346,7 @@ PG_KEYWORD("procedures", PROCEDURES, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("program", PROGRAM, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("publication", PUBLICATION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("quote", QUOTE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("quotes", QUOTES, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("range", RANGE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("read", READ, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("real", REAL, COL_NAME_KEYWORD, BARE_LABEL)
@@ -408,6 +417,7 @@ PG_KEYWORD("stdout", STDOUT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("storage", STORAGE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("stored", STORED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("strict", STRICT_P, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("string", STRING, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("strip", STRIP_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("subscription", SUBSCRIPTION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("substring", SUBSTRING, COL_NAME_KEYWORD, BARE_LABEL)
@@ -442,6 +452,7 @@ PG_KEYWORD("types", TYPES_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("uescape", UESCAPE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("unbounded", UNBOUNDED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("uncommitted", UNCOMMITTED, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("unconditional", UNCONDITIONAL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("unencrypted", UNENCRYPTED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("union", UNION, RESERVED_KEYWORD, AS_LABEL)
 PG_KEYWORD("unique", UNIQUE, RESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/formatting.h b/src/include/utils/formatting.h
index 93f979f320..c20a6a6d5f 100644
--- a/src/include/utils/formatting.h
+++ b/src/include/utils/formatting.h
@@ -17,6 +17,9 @@
 #ifndef _FORMATTING_H_
 #define _FORMATTING_H_
 
+#define DCH_DATED	0x01
+#define DCH_TIMED	0x02
+#define DCH_ZONED	0x04
 
 extern char *str_tolower(const char *buff, size_t nbytes, Oid collid);
 extern char *str_toupper(const char *buff, size_t nbytes, Oid collid);
@@ -29,5 +32,6 @@ extern char *asc_initcap(const char *buff, size_t nbytes);
 extern Datum parse_datetime(text *date_txt, text *fmt, Oid collid, bool strict,
 							Oid *typid, int32 *typmod, int *tz,
 							bool *have_error);
+extern int datetime_format_flags(const char *fmt_str, bool *have_error);
 
 #endif
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index d2122917aa..0a00748f04 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -407,6 +407,9 @@ extern char *JsonbToCString(StringInfo out, JsonbContainer *in,
 							int estimated_len);
 extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 								  int estimated_len);
+extern Jsonb *JsonbMakeEmptyArray(void);
+extern Jsonb *JsonbMakeEmptyObject(void);
+extern char *JsonbUnquote(Jsonb *jb);
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
diff --git a/src/include/utils/jsonfuncs.h b/src/include/utils/jsonfuncs.h
index f20c138050..9e9128e8b2 100644
--- a/src/include/utils/jsonfuncs.h
+++ b/src/include/utils/jsonfuncs.h
@@ -58,4 +58,8 @@ extern Jsonb *transform_jsonb_string_values(Jsonb *jsonb, void *action_state,
 extern text *transform_json_string_values(text *json, void *action_state,
 										  JsonTransformStringValuesAction transform_action);
 
+extern Datum json_populate_type(Datum json_val, Oid json_type,
+								Oid typid, int32 typmod,
+								void **cache, MemoryContext mcxt, bool *isnull);
+
 #endif
diff --git a/src/include/utils/jsonpath.h b/src/include/utils/jsonpath.h
index 87d302b702..fd2663c22f 100644
--- a/src/include/utils/jsonpath.h
+++ b/src/include/utils/jsonpath.h
@@ -16,7 +16,9 @@
 
 #include "fmgr.h"
 #include "nodes/pg_list.h"
+#include "nodes/primnodes.h"
 #include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
 
 typedef struct
 {
@@ -174,6 +176,7 @@ extern bool jspGetBool(JsonPathItem *v);
 extern char *jspGetString(JsonPathItem *v, int32 *len);
 extern bool jspGetArraySubscript(JsonPathItem *v, JsonPathItem *from,
 								 JsonPathItem *to, int i);
+extern bool jspIsMutable(JsonPath *path, List *varnames, List *varexprs);
 
 extern const char *jspOperationName(JsonPathItemType type);
 
@@ -248,4 +251,34 @@ extern JsonPathParseResult *parsejsonpath(const char *str, int len);
 
 extern int	jspConvertRegexFlags(uint32 xflags);
 
+/*
+ * Evaluation of jsonpath
+ */
+
+/* External variable passed into jsonpath. */
+typedef struct JsonPathVariableEvalContext
+{
+	char	   *name;
+	Oid			typid;
+	int32		typmod;
+	struct ExprContext *econtext;
+	struct ExprState  *estate;
+	Datum		value;
+	bool		isnull;
+	bool		evaluated;
+} JsonPathVariableEvalContext;
+
+/* SQL/JSON item */
+extern void JsonItemFromDatum(Datum val, Oid typid, int32 typmod,
+							  JsonbValue *res);
+
+extern bool  JsonPathExists(Datum jb, JsonPath *path, List *vars, bool *error);
+extern Datum JsonPathQuery(Datum jb, JsonPath *jp, JsonWrapper wrapper,
+						   bool *empty, bool *error, List *vars);
+extern JsonbValue *JsonPathValue(Datum jb, JsonPath *jp, bool *empty,
+								 bool *error, List *vars);
+
+extern int EvalJsonPathVar(void *vars, char *varName, int varNameLen,
+						   JsonbValue *val, JsonbValue *baseObject);
+
 #endif
diff --git a/src/test/regress/expected/json_sqljson.out b/src/test/regress/expected/json_sqljson.out
new file mode 100644
index 0000000000..bb62634314
--- /dev/null
+++ b/src/test/regress/expected/json_sqljson.out
@@ -0,0 +1,15 @@
+-- JSON_EXISTS
+SELECT JSON_EXISTS(NULL FORMAT JSON, '$');
+ERROR:  JSON_EXISTS() is not yet implemented for json type
+LINE 1: SELECT JSON_EXISTS(NULL FORMAT JSON, '$');
+               ^
+-- JSON_VALUE
+SELECT JSON_VALUE(NULL FORMAT JSON, '$');
+ERROR:  JSON_VALUE() is not yet implemented for json type
+LINE 1: SELECT JSON_VALUE(NULL FORMAT JSON, '$');
+               ^
+-- JSON_QUERY
+SELECT JSON_QUERY(NULL FORMAT JSON, '$');
+ERROR:  JSON_QUERY() is not yet implemented for json type
+LINE 1: SELECT JSON_QUERY(NULL FORMAT JSON, '$');
+               ^
diff --git a/src/test/regress/expected/jsonb_sqljson.out b/src/test/regress/expected/jsonb_sqljson.out
new file mode 100644
index 0000000000..f2f5e271b8
--- /dev/null
+++ b/src/test/regress/expected/jsonb_sqljson.out
@@ -0,0 +1,1018 @@
+-- JSON_EXISTS
+SELECT JSON_EXISTS(NULL::jsonb, '$');
+ json_exists 
+-------------
+ 
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[]', '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(JSON_OBJECT(RETURNING jsonb), '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb 'null', '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[]', '$');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', 'strict $.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', 'strict $.a' ERROR ON ERROR);
+ERROR:  jsonpath member accessor can only be applied to an object
+SELECT JSON_EXISTS(jsonb 'null', '$.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[]', '$.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[1, "aaa", {"a": 1}]', 'strict $.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '[1, "aaa", {"a": 1}]', 'lax $.a');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{}', '$.a');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"b": 1, "a": 2}', '$.a');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$.a.b');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": {"b": 1}}', '$.a.b');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.a.b');
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x)' PASSING 1 AS x);
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x)' PASSING '1' AS x);
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x && @ < $y)' PASSING 0 AS x, 2 AS y);
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x && @ < $y)' PASSING 0 AS x, 1 AS y);
+ json_exists 
+-------------
+ f
+(1 row)
+
+-- extension: boolean expressions
+SELECT JSON_EXISTS(jsonb '1', '$ > 2');
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$.a > 2' ERROR ON ERROR);
+ json_exists 
+-------------
+ t
+(1 row)
+
+-- extension: RETURNING clause
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING bool);
+ json_exists 
+-------------
+ t
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$[1]' RETURNING bool);
+ json_exists 
+-------------
+ f
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING int);
+ json_exists 
+-------------
+           1
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$[1]' RETURNING int);
+ json_exists 
+-------------
+           0
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING text);
+ json_exists 
+-------------
+ true
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$[1]' RETURNING text);
+ json_exists 
+-------------
+ false
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', 'strict $[1]' RETURNING text FALSE ON ERROR);
+ json_exists 
+-------------
+ false
+(1 row)
+
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING jsonb);
+ERROR:  cannot cast type boolean to jsonb
+LINE 1: SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING jsonb);
+               ^
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING float4);
+ERROR:  cannot cast type boolean to real
+LINE 1: SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING float4);
+               ^
+-- JSON_VALUE
+SELECT JSON_VALUE(NULL::jsonb, '$');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$' RETURNING int);
+ json_value 
+------------
+           
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'true', '$');
+ json_value 
+------------
+ true
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'true', '$' RETURNING bool);
+ json_value 
+------------
+ t
+(1 row)
+
+SELECT JSON_VALUE(jsonb '123', '$');
+ json_value 
+------------
+ 123
+(1 row)
+
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING int) + 234;
+ ?column? 
+----------
+      357
+(1 row)
+
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING text);
+ json_value 
+------------
+ 123
+(1 row)
+
+/* jsonb bytea ??? */
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING bytea ERROR ON ERROR);
+ERROR:  SQL/JSON item cannot be cast to target type
+SELECT JSON_VALUE(jsonb '1.23', '$');
+ json_value 
+------------
+ 1.23
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1.23', '$' RETURNING int);
+ json_value 
+------------
+          1
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"1.23"', '$' RETURNING numeric);
+ json_value 
+------------
+       1.23
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"1.23"', '$' RETURNING int ERROR ON ERROR);
+ERROR:  invalid input syntax for type integer: "1.23"
+SELECT JSON_VALUE(jsonb '"aaa"', '$');
+ json_value 
+------------
+ aaa
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING text);
+ json_value 
+------------
+ aaa
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING char(5));
+ json_value 
+------------
+ aaa  
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING char(2));
+ json_value 
+------------
+ aa
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING json);
+ json_value 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING jsonb);
+ json_value 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING json ERROR ON ERROR);
+ json_value 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING jsonb ERROR ON ERROR);
+ json_value 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"\"aaa\""', '$' RETURNING json);
+ json_value 
+------------
+ "\"aaa\""
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"\"aaa\""', '$' RETURNING jsonb);
+ json_value 
+------------
+ "\"aaa\""
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int);
+ json_value 
+------------
+           
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int ERROR ON ERROR);
+ERROR:  invalid input syntax for type integer: "aaa"
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int DEFAULT 111 ON ERROR);
+ json_value 
+------------
+        111
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"123"', '$' RETURNING int) + 234;
+ ?column? 
+----------
+      357
+(1 row)
+
+SELECT JSON_VALUE(jsonb '"2017-02-20"', '$' RETURNING date) + 9;
+  ?column?  
+------------
+ 03-01-2017
+(1 row)
+
+-- Test NULL checks execution in domain types
+CREATE DOMAIN sqljsonb_int_not_null AS int NOT NULL;
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null);
+ERROR:  domain sqljsonb_int_not_null does not allow null values
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null NULL ON ERROR);
+ERROR:  domain sqljsonb_int_not_null does not allow null values
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null DEFAULT NULL ON ERROR);
+ERROR:  domain sqljsonb_int_not_null does not allow null values
+SELECT JSON_VALUE(jsonb '[]', '$');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '[]', '$' ERROR ON ERROR);
+ERROR:  JSON path expression in JSON_VALUE should return singleton scalar item
+SELECT JSON_VALUE(jsonb '{}', '$');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '{}', '$' ERROR ON ERROR);
+ERROR:  JSON path expression in JSON_VALUE should return singleton scalar item
+SELECT JSON_VALUE(jsonb '1', '$.a');
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' ERROR ON ERROR);
+ERROR:  jsonpath member accessor can only be applied to an object
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' DEFAULT 'error' ON ERROR);
+ json_value 
+------------
+ error
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON ERROR);
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY ERROR ON ERROR);
+ERROR:  no SQL/JSON item
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' DEFAULT 2 ON ERROR);
+ json_value 
+------------
+ 2
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT 2 ON ERROR);
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON ERROR);
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' NULL ON EMPTY DEFAULT '2' ON ERROR);
+ json_value 
+------------
+ 
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON EMPTY DEFAULT '3' ON ERROR);
+ json_value 
+------------
+ 2
+(1 row)
+
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY DEFAULT '3' ON ERROR);
+ json_value 
+------------
+ 3
+(1 row)
+
+SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
+ERROR:  JSON path expression in JSON_VALUE should return singleton scalar item
+SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' DEFAULT '0' ON ERROR);
+ json_value 
+------------
+ 0
+(1 row)
+
+SELECT JSON_VALUE(jsonb '[" "]', '$[*]' RETURNING int ERROR ON ERROR);
+ERROR:  invalid input syntax for type integer: " "
+SELECT JSON_VALUE(jsonb '[" "]', '$[*]' RETURNING int DEFAULT 2 + 3 ON ERROR);
+ json_value 
+------------
+          5
+(1 row)
+
+SELECT JSON_VALUE(jsonb '["1"]', '$[*]' RETURNING int DEFAULT 2 + 3 ON ERROR);
+ json_value 
+------------
+          1
+(1 row)
+
+SELECT
+	x,
+	JSON_VALUE(
+		jsonb '{"a": 1, "b": 2}',
+		'$.* ? (@ > $x)' PASSING x AS x
+		RETURNING int
+		DEFAULT -1 ON EMPTY
+		DEFAULT -2 ON ERROR
+	) y
+FROM
+	generate_series(0, 2) x;
+ x | y  
+---+----
+ 0 | -2
+ 1 |  2
+ 2 | -1
+(3 rows)
+
+SELECT JSON_VALUE(jsonb 'null', '$a' PASSING point ' (1, 2 )' AS a);
+ json_value 
+------------
+ (1,2)
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$a' PASSING point ' (1, 2 )' AS a RETURNING point);
+ json_value 
+------------
+ (1,2)
+(1 row)
+
+-- Test timestamptz passing and output
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts);
+          json_value          
+------------------------------
+ Tue Feb 20 18:34:56 2018 PST
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING timestamptz);
+          json_value          
+------------------------------
+ Tue Feb 20 18:34:56 2018 PST
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING timestamp);
+        json_value        
+--------------------------
+ Tue Feb 20 18:34:56 2018
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING json);
+         json_value          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING jsonb);
+         json_value          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+-- JSON_QUERY
+SELECT
+	JSON_QUERY(js, '$'),
+	JSON_QUERY(js, '$' WITHOUT WRAPPER),
+	JSON_QUERY(js, '$' WITH CONDITIONAL WRAPPER),
+	JSON_QUERY(js, '$' WITH UNCONDITIONAL ARRAY WRAPPER),
+	JSON_QUERY(js, '$' WITH ARRAY WRAPPER)
+FROM
+	(VALUES
+		(jsonb 'null'),
+		('12.3'),
+		('true'),
+		('"aaa"'),
+		('[1, null, "2"]'),
+		('{"a": 1, "b": [2]}')
+	) foo(js);
+     json_query     |     json_query     |     json_query     |      json_query      |      json_query      
+--------------------+--------------------+--------------------+----------------------+----------------------
+ null               | null               | [null]             | [null]               | [null]
+ 12.3               | 12.3               | [12.3]             | [12.3]               | [12.3]
+ true               | true               | [true]             | [true]               | [true]
+ "aaa"              | "aaa"              | ["aaa"]            | ["aaa"]              | ["aaa"]
+ [1, null, "2"]     | [1, null, "2"]     | [1, null, "2"]     | [[1, null, "2"]]     | [[1, null, "2"]]
+ {"a": 1, "b": [2]} | {"a": 1, "b": [2]} | {"a": 1, "b": [2]} | [{"a": 1, "b": [2]}] | [{"a": 1, "b": [2]}]
+(6 rows)
+
+SELECT
+	JSON_QUERY(js, 'strict $[*]') AS "unspec",
+	JSON_QUERY(js, 'strict $[*]' WITHOUT WRAPPER) AS "without",
+	JSON_QUERY(js, 'strict $[*]' WITH CONDITIONAL WRAPPER) AS "with cond",
+	JSON_QUERY(js, 'strict $[*]' WITH UNCONDITIONAL ARRAY WRAPPER) AS "with uncond",
+	JSON_QUERY(js, 'strict $[*]' WITH ARRAY WRAPPER) AS "with"
+FROM
+	(VALUES
+		(jsonb '1'),
+		('[]'),
+		('[null]'),
+		('[12.3]'),
+		('[true]'),
+		('["aaa"]'),
+		('[[1, 2, 3]]'),
+		('[{"a": 1, "b": [2]}]'),
+		('[1, "2", null, [3]]')
+	) foo(js);
+       unspec       |      without       |      with cond      |     with uncond      |         with         
+--------------------+--------------------+---------------------+----------------------+----------------------
+                    |                    |                     |                      | 
+                    |                    |                     |                      | 
+ null               | null               | [null]              | [null]               | [null]
+ 12.3               | 12.3               | [12.3]              | [12.3]               | [12.3]
+ true               | true               | [true]              | [true]               | [true]
+ "aaa"              | "aaa"              | ["aaa"]             | ["aaa"]              | ["aaa"]
+ [1, 2, 3]          | [1, 2, 3]          | [1, 2, 3]           | [[1, 2, 3]]          | [[1, 2, 3]]
+ {"a": 1, "b": [2]} | {"a": 1, "b": [2]} | {"a": 1, "b": [2]}  | [{"a": 1, "b": [2]}] | [{"a": 1, "b": [2]}]
+                    |                    | [1, "2", null, [3]] | [1, "2", null, [3]]  | [1, "2", null, [3]]
+(9 rows)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text);
+ json_query 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text KEEP QUOTES);
+ json_query 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text KEEP QUOTES ON SCALAR STRING);
+ json_query 
+------------
+ "aaa"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES);
+ json_query 
+------------
+ aaa
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES ON SCALAR STRING);
+ json_query 
+------------
+ aaa
+(1 row)
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' OMIT QUOTES ERROR ON ERROR);
+ERROR:  invalid input syntax for type json
+DETAIL:  Token "aaa" is invalid.
+CONTEXT:  JSON data, line 1: aaa
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING json OMIT QUOTES ERROR ON ERROR);
+ERROR:  invalid input syntax for type json
+DETAIL:  Token "aaa" is invalid.
+CONTEXT:  JSON data, line 1: aaa
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING bytea FORMAT JSON OMIT QUOTES ERROR ON ERROR);
+ json_query 
+------------
+ \x616161
+(1 row)
+
+-- QUOTES behavior should not be specified when WITH WRAPPER used:
+-- Should fail
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER OMIT QUOTES);
+ERROR:  SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used
+LINE 1: SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER OMIT QUOTES)...
+                                                        ^
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER KEEP QUOTES);
+ERROR:  SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used
+LINE 1: SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER KEEP QUOTES)...
+                                                        ^
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER KEEP QUOTES);
+ERROR:  SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used
+LINE 1: ...N_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER KEEP QUOTE...
+                                                             ^
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER OMIT QUOTES);
+ERROR:  SQL/JSON QUOTES behavior shall not be specified when WITH WRAPPER is used
+LINE 1: ...N_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER OMIT QUOTE...
+                                                             ^
+-- Should succeed
+SELECT JSON_QUERY(jsonb '[1]', '$' WITHOUT WRAPPER OMIT QUOTES);
+ json_query 
+------------
+ [1]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1]', '$' WITHOUT WRAPPER KEEP QUOTES);
+ json_query 
+------------
+ [1]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]');
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' NULL ON EMPTY);
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY ON EMPTY);
+ json_query 
+------------
+ []
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY ARRAY ON EMPTY);
+ json_query 
+------------
+ []
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY OBJECT ON EMPTY);
+ json_query 
+------------
+ {}
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY);
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' DEFAULT '"empty"' ON EMPTY);
+ json_query 
+------------
+ "empty"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY NULL ON ERROR);
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY EMPTY ARRAY ON ERROR);
+ json_query 
+------------
+ []
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ {}
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY ERROR ON ERROR);
+ERROR:  no SQL/JSON item
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON ERROR);
+ json_query 
+------------
+ 
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
+ERROR:  JSON path expression in JSON_QUERY should return singleton item without wrapper
+HINT:  use WITH WRAPPER clause to wrap SQL/JSON item sequence into array
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' DEFAULT '"empty"' ON ERROR);
+ json_query 
+------------
+ "empty"
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING json);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING json FORMAT JSON);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING jsonb);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING jsonb FORMAT JSON);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING text);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING char(10));
+ json_query 
+------------
+ [1, 2]    
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING char(3));
+ json_query 
+------------
+ [1,
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING text FORMAT JSON);
+ json_query 
+------------
+ [1, 2]
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING bytea);
+   json_query   
+----------------
+ \x5b312c20325d
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING bytea FORMAT JSON);
+   json_query   
+----------------
+ \x5b312c20325d
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING bytea EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ \x7b7d
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING bytea FORMAT JSON EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ \x7b7d
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING json EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ {}
+(1 row)
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING jsonb EMPTY OBJECT ON ERROR);
+ json_query 
+------------
+ {}
+(1 row)
+
+SELECT
+	x, y,
+	JSON_QUERY(
+		jsonb '[1,2,3,4,5,null]',
+		'$[*] ? (@ >= $x && @ <= $y)'
+		PASSING x AS x, y AS y
+		WITH CONDITIONAL WRAPPER
+		EMPTY ARRAY ON EMPTY
+	) list
+FROM
+	generate_series(0, 4) x,
+	generate_series(0, 4) y;
+ x | y |     list     
+---+---+--------------
+ 0 | 0 | []
+ 0 | 1 | [1]
+ 0 | 2 | [1, 2]
+ 0 | 3 | [1, 2, 3]
+ 0 | 4 | [1, 2, 3, 4]
+ 1 | 0 | []
+ 1 | 1 | [1]
+ 1 | 2 | [1, 2]
+ 1 | 3 | [1, 2, 3]
+ 1 | 4 | [1, 2, 3, 4]
+ 2 | 0 | []
+ 2 | 1 | []
+ 2 | 2 | [2]
+ 2 | 3 | [2, 3]
+ 2 | 4 | [2, 3, 4]
+ 3 | 0 | []
+ 3 | 1 | []
+ 3 | 2 | []
+ 3 | 3 | [3]
+ 3 | 4 | [3, 4]
+ 4 | 0 | []
+ 4 | 1 | []
+ 4 | 2 | []
+ 4 | 3 | []
+ 4 | 4 | [4]
+(25 rows)
+
+-- Extension: record types returning
+CREATE TYPE sqljsonb_rec AS (a int, t text, js json, jb jsonb, jsa json[]);
+CREATE TYPE sqljsonb_reca AS (reca sqljsonb_rec[]);
+SELECT JSON_QUERY(jsonb '[{"a": 1, "b": "foo", "t": "aaa", "js": [1, "2", {}], "jb": {"x": [1, "2", {}]}},  {"a": 2}]', '$[0]' RETURNING sqljsonb_rec);
+                     json_query                      
+-----------------------------------------------------
+ (1,aaa,"[1, ""2"", {}]","{""x"": [1, ""2"", {}]}",)
+(1 row)
+
+SELECT * FROM unnest((JSON_QUERY(jsonb '{"jsa":  [{"a": 1, "b": ["foo"]}, {"a": 2, "c": {}}, 123]}', '$' RETURNING sqljsonb_rec)).jsa);
+         unnest         
+------------------------
+ {"a": 1, "b": ["foo"]}
+ {"a": 2, "c": {}}
+ 123
+(3 rows)
+
+SELECT * FROM unnest((JSON_QUERY(jsonb '{"reca": [{"a": 1, "t": ["foo", []]}, {"a": 2, "jb": [{}, true]}]}', '$' RETURNING sqljsonb_reca)).reca);
+ a |      t      | js |     jb     | jsa 
+---+-------------+----+------------+-----
+ 1 | ["foo", []] |    |            | 
+ 2 |             |    | [{}, true] | 
+(2 rows)
+
+-- Extension: array types returning
+SELECT JSON_QUERY(jsonb '[1,2,null,"3"]', '$[*]' RETURNING int[] WITH WRAPPER);
+  json_query  
+--------------
+ {1,2,NULL,3}
+(1 row)
+
+SELECT * FROM unnest(JSON_QUERY(jsonb '[{"a": 1, "t": ["foo", []]}, {"a": 2, "jb": [{}, true]}]', '$' RETURNING sqljsonb_rec[]));
+ a |      t      | js |     jb     | jsa 
+---+-------------+----+------------+-----
+ 1 | ["foo", []] |    |            | 
+ 2 |             |    | [{}, true] | 
+(2 rows)
+
+-- Extension: domain types returning
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.a' RETURNING sqljsonb_int_not_null);
+ json_query 
+------------
+          1
+(1 row)
+
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.b' RETURNING sqljsonb_int_not_null);
+ERROR:  domain sqljsonb_int_not_null does not allow null values
+-- Test timestamptz passing and output
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts);
+         json_query          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING json);
+         json_query          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING jsonb);
+         json_query          
+-----------------------------
+ "2018-02-21T02:34:56+00:00"
+(1 row)
+
+-- Test constraints
+CREATE TABLE test_jsonb_constraints (
+	js text,
+	i int,
+	x jsonb DEFAULT JSON_QUERY(jsonb '[1,2]', '$[*]' WITH WRAPPER)
+	CONSTRAINT test_jsonb_constraint1
+		CHECK (js IS JSON)
+	CONSTRAINT test_jsonb_constraint2
+		CHECK (JSON_EXISTS(js::jsonb, '$.a' PASSING i + 5 AS int, i::text AS txt, array[1,2,3] as arr))
+	CONSTRAINT test_jsonb_constraint3
+		CHECK (JSON_VALUE(js::jsonb, '$.a' RETURNING int DEFAULT ('12' || i)::int ON EMPTY ERROR ON ERROR) > i)
+	CONSTRAINT test_jsonb_constraint4
+		CHECK (JSON_QUERY(js::jsonb, '$.a' WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) < jsonb '[10]')
+	CONSTRAINT test_jsonb_constraint5
+		CHECK (JSON_QUERY(js::jsonb, '$.a' RETURNING char(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) >  'a' COLLATE "C")
+	CONSTRAINT test_jsonb_constraint6
+		CHECK (JSON_EXISTS(js::jsonb, 'strict $.a' RETURNING int TRUE ON ERROR) < 2)
+);
+\d test_jsonb_constraints
+                                          Table "public.test_jsonb_constraints"
+ Column |  Type   | Collation | Nullable |                                    Default                                     
+--------+---------+-----------+----------+--------------------------------------------------------------------------------
+ js     | text    |           |          | 
+ i      | integer |           |          | 
+ x      | jsonb   |           |          | JSON_QUERY('[1, 2]'::jsonb, '$[*]' RETURNING jsonb WITH UNCONDITIONAL WRAPPER)
+Check constraints:
+    "test_jsonb_constraint1" CHECK (js IS JSON)
+    "test_jsonb_constraint2" CHECK (JSON_EXISTS(js::jsonb, '$."a"' PASSING i + 5 AS int, i::text AS txt, ARRAY[1, 2, 3] AS arr))
+    "test_jsonb_constraint3" CHECK (JSON_VALUE(js::jsonb, '$."a"' RETURNING integer DEFAULT ('12'::text || i)::integer ON EMPTY ERROR ON ERROR) > i)
+    "test_jsonb_constraint4" CHECK (JSON_QUERY(js::jsonb, '$."a"' RETURNING jsonb WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) < '[10]'::jsonb)
+    "test_jsonb_constraint5" CHECK (JSON_QUERY(js::jsonb, '$."a"' RETURNING character(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) > ('a'::bpchar COLLATE "C"))
+    "test_jsonb_constraint6" CHECK (JSON_EXISTS(js::jsonb, 'strict $."a"' RETURNING integer TRUE ON ERROR) < 2)
+
+SELECT check_clause
+FROM information_schema.check_constraints
+WHERE constraint_name LIKE 'test_jsonb_constraint%';
+                                                       check_clause                                                       
+--------------------------------------------------------------------------------------------------------------------------
+ ((js IS JSON))
+ (JSON_EXISTS((js)::jsonb, '$."a"' PASSING (i + 5) AS int, (i)::text AS txt, ARRAY[1, 2, 3] AS arr))
+ ((JSON_VALUE((js)::jsonb, '$."a"' RETURNING integer DEFAULT (('12'::text || i))::integer ON EMPTY ERROR ON ERROR) > i))
+ ((JSON_QUERY((js)::jsonb, '$."a"' RETURNING jsonb WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) < '[10]'::jsonb))
+ ((JSON_QUERY((js)::jsonb, '$."a"' RETURNING character(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) > ('a'::bpchar COLLATE "C")))
+ ((JSON_EXISTS((js)::jsonb, 'strict $."a"' RETURNING integer TRUE ON ERROR) < 2))
+(6 rows)
+
+SELECT pg_get_expr(adbin, adrelid) FROM pg_attrdef WHERE adrelid = 'test_jsonb_constraints'::regclass;
+                                  pg_get_expr                                   
+--------------------------------------------------------------------------------
+ JSON_QUERY('[1, 2]'::jsonb, '$[*]' RETURNING jsonb WITH UNCONDITIONAL WRAPPER)
+(1 row)
+
+INSERT INTO test_jsonb_constraints VALUES ('', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint1"
+DETAIL:  Failing row contains (, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('1', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint2"
+DETAIL:  Failing row contains (1, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('[]');
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint2"
+DETAIL:  Failing row contains ([], null, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('{"b": 1}', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint2"
+DETAIL:  Failing row contains ({"b": 1}, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 1}', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint3"
+DETAIL:  Failing row contains ({"a": 1}, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 7}', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint5"
+DETAIL:  Failing row contains ({"a": 7}, 1, [1, 2]).
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 10}', 1);
+ERROR:  new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint4"
+DETAIL:  Failing row contains ({"a": 10}, 1, [1, 2]).
+DROP TABLE test_jsonb_constraints;
+-- Test mutabilily od query functions
+CREATE TABLE test_jsonb_mutability(js jsonb);
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a[0]'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime()'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@ < $.datetime())'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime() < $.datetime())'));
+ERROR:  functions in index expression must be marked IMMUTABLE
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime() < $.datetime("HH:MI TZH"))'));
+ERROR:  functions in index expression must be marked IMMUTABLE
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime("HH:MI TZH") < $.datetime("HH:MI TZH"))'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime("HH:MI") < $.datetime("YY-MM-DD HH:MI"))'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime("HH:MI TZH") < $.datetime("YY-MM-DD HH:MI"))'));
+ERROR:  functions in index expression must be marked IMMUTABLE
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime("HH:MI TZH") < $x' PASSING '12:34'::timetz AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime("HH:MI TZH") < $y' PASSING '12:34'::timetz AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime() < $x' PASSING '12:34'::timetz AS x));
+ERROR:  functions in index expression must be marked IMMUTABLE
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime() < $x' PASSING '1234'::int AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime() ? (@ == $x)' PASSING '12:34'::time AS x));
+ERROR:  functions in index expression must be marked IMMUTABLE
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime("YY-MM-DD") ? (@ == $x)' PASSING '2020-07-14'::date AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$[1, $.a ? (@.datetime() == $x)]' PASSING '12:34'::time AS x));
+ERROR:  functions in index expression must be marked IMMUTABLE
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$[1, 0 to $.a ? (@.datetime() == $x)]' PASSING '12:34'::time AS x));
+ERROR:  functions in index expression must be marked IMMUTABLE
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$[1, $.a ? (@.datetime("HH:MI") == $x)]' PASSING '12:34'::time AS x));
+DROP TABLE test_jsonb_mutability;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 59f5b209e7..810450164d 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -108,7 +108,7 @@ test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combo
 # ----------
 # Another group of parallel tests (JSON related)
 # ----------
-test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
+test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson json_sqljson jsonb_sqljson
 
 # ----------
 # Another group of parallel tests
diff --git a/src/test/regress/sql/json_sqljson.sql b/src/test/regress/sql/json_sqljson.sql
new file mode 100644
index 0000000000..4f30fa46b9
--- /dev/null
+++ b/src/test/regress/sql/json_sqljson.sql
@@ -0,0 +1,11 @@
+-- JSON_EXISTS
+
+SELECT JSON_EXISTS(NULL FORMAT JSON, '$');
+
+-- JSON_VALUE
+
+SELECT JSON_VALUE(NULL FORMAT JSON, '$');
+
+-- JSON_QUERY
+
+SELECT JSON_QUERY(NULL FORMAT JSON, '$');
diff --git a/src/test/regress/sql/jsonb_sqljson.sql b/src/test/regress/sql/jsonb_sqljson.sql
new file mode 100644
index 0000000000..00a067a06a
--- /dev/null
+++ b/src/test/regress/sql/jsonb_sqljson.sql
@@ -0,0 +1,317 @@
+-- JSON_EXISTS
+
+SELECT JSON_EXISTS(NULL::jsonb, '$');
+
+SELECT JSON_EXISTS(jsonb '[]', '$');
+SELECT JSON_EXISTS(JSON_OBJECT(RETURNING jsonb), '$');
+
+SELECT JSON_EXISTS(jsonb '1', '$');
+SELECT JSON_EXISTS(jsonb 'null', '$');
+SELECT JSON_EXISTS(jsonb '[]', '$');
+
+SELECT JSON_EXISTS(jsonb '1', '$.a');
+SELECT JSON_EXISTS(jsonb '1', 'strict $.a');
+SELECT JSON_EXISTS(jsonb '1', 'strict $.a' ERROR ON ERROR);
+SELECT JSON_EXISTS(jsonb 'null', '$.a');
+SELECT JSON_EXISTS(jsonb '[]', '$.a');
+SELECT JSON_EXISTS(jsonb '[1, "aaa", {"a": 1}]', 'strict $.a');
+SELECT JSON_EXISTS(jsonb '[1, "aaa", {"a": 1}]', 'lax $.a');
+SELECT JSON_EXISTS(jsonb '{}', '$.a');
+SELECT JSON_EXISTS(jsonb '{"b": 1, "a": 2}', '$.a');
+
+SELECT JSON_EXISTS(jsonb '1', '$.a.b');
+SELECT JSON_EXISTS(jsonb '{"a": {"b": 1}}', '$.a.b');
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.a.b');
+
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x)' PASSING 1 AS x);
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x)' PASSING '1' AS x);
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x && @ < $y)' PASSING 0 AS x, 2 AS y);
+SELECT JSON_EXISTS(jsonb '{"a": 1, "b": 2}', '$.* ? (@ > $x && @ < $y)' PASSING 0 AS x, 1 AS y);
+
+-- extension: boolean expressions
+SELECT JSON_EXISTS(jsonb '1', '$ > 2');
+SELECT JSON_EXISTS(jsonb '1', '$.a > 2' ERROR ON ERROR);
+
+-- extension: RETURNING clause
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING bool);
+SELECT JSON_EXISTS(jsonb '1', '$[1]' RETURNING bool);
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING int);
+SELECT JSON_EXISTS(jsonb '1', '$[1]' RETURNING int);
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING text);
+SELECT JSON_EXISTS(jsonb '1', '$[1]' RETURNING text);
+SELECT JSON_EXISTS(jsonb '1', 'strict $[1]' RETURNING text FALSE ON ERROR);
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING jsonb);
+SELECT JSON_EXISTS(jsonb '1', '$[0]' RETURNING float4);
+
+
+-- JSON_VALUE
+
+SELECT JSON_VALUE(NULL::jsonb, '$');
+
+SELECT JSON_VALUE(jsonb 'null', '$');
+SELECT JSON_VALUE(jsonb 'null', '$' RETURNING int);
+
+SELECT JSON_VALUE(jsonb 'true', '$');
+SELECT JSON_VALUE(jsonb 'true', '$' RETURNING bool);
+
+SELECT JSON_VALUE(jsonb '123', '$');
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING int) + 234;
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING text);
+/* jsonb bytea ??? */
+SELECT JSON_VALUE(jsonb '123', '$' RETURNING bytea ERROR ON ERROR);
+
+SELECT JSON_VALUE(jsonb '1.23', '$');
+SELECT JSON_VALUE(jsonb '1.23', '$' RETURNING int);
+SELECT JSON_VALUE(jsonb '"1.23"', '$' RETURNING numeric);
+SELECT JSON_VALUE(jsonb '"1.23"', '$' RETURNING int ERROR ON ERROR);
+
+SELECT JSON_VALUE(jsonb '"aaa"', '$');
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING text);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING char(5));
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING char(2));
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING json);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING jsonb);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING json ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING jsonb ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '"\"aaa\""', '$' RETURNING json);
+SELECT JSON_VALUE(jsonb '"\"aaa\""', '$' RETURNING jsonb);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '"aaa"', '$' RETURNING int DEFAULT 111 ON ERROR);
+SELECT JSON_VALUE(jsonb '"123"', '$' RETURNING int) + 234;
+
+SELECT JSON_VALUE(jsonb '"2017-02-20"', '$' RETURNING date) + 9;
+
+-- Test NULL checks execution in domain types
+CREATE DOMAIN sqljsonb_int_not_null AS int NOT NULL;
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null);
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null NULL ON ERROR);
+SELECT JSON_VALUE(jsonb '1', '$.a' RETURNING sqljsonb_int_not_null DEFAULT NULL ON ERROR);
+
+SELECT JSON_VALUE(jsonb '[]', '$');
+SELECT JSON_VALUE(jsonb '[]', '$' ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '{}', '$');
+SELECT JSON_VALUE(jsonb '{}', '$' ERROR ON ERROR);
+
+SELECT JSON_VALUE(jsonb '1', '$.a');
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' DEFAULT 'error' ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'strict $.a' DEFAULT 2 ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT 2 ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' NULL ON EMPTY DEFAULT '2' ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON EMPTY DEFAULT '3' ON ERROR);
+SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY DEFAULT '3' ON ERROR);
+
+SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' DEFAULT '0' ON ERROR);
+SELECT JSON_VALUE(jsonb '[" "]', '$[*]' RETURNING int ERROR ON ERROR);
+SELECT JSON_VALUE(jsonb '[" "]', '$[*]' RETURNING int DEFAULT 2 + 3 ON ERROR);
+SELECT JSON_VALUE(jsonb '["1"]', '$[*]' RETURNING int DEFAULT 2 + 3 ON ERROR);
+
+SELECT
+	x,
+	JSON_VALUE(
+		jsonb '{"a": 1, "b": 2}',
+		'$.* ? (@ > $x)' PASSING x AS x
+		RETURNING int
+		DEFAULT -1 ON EMPTY
+		DEFAULT -2 ON ERROR
+	) y
+FROM
+	generate_series(0, 2) x;
+
+SELECT JSON_VALUE(jsonb 'null', '$a' PASSING point ' (1, 2 )' AS a);
+SELECT JSON_VALUE(jsonb 'null', '$a' PASSING point ' (1, 2 )' AS a RETURNING point);
+
+-- Test timestamptz passing and output
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts);
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING timestamptz);
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING timestamp);
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING json);
+SELECT JSON_VALUE(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING jsonb);
+
+-- JSON_QUERY
+
+SELECT
+	JSON_QUERY(js, '$'),
+	JSON_QUERY(js, '$' WITHOUT WRAPPER),
+	JSON_QUERY(js, '$' WITH CONDITIONAL WRAPPER),
+	JSON_QUERY(js, '$' WITH UNCONDITIONAL ARRAY WRAPPER),
+	JSON_QUERY(js, '$' WITH ARRAY WRAPPER)
+FROM
+	(VALUES
+		(jsonb 'null'),
+		('12.3'),
+		('true'),
+		('"aaa"'),
+		('[1, null, "2"]'),
+		('{"a": 1, "b": [2]}')
+	) foo(js);
+
+SELECT
+	JSON_QUERY(js, 'strict $[*]') AS "unspec",
+	JSON_QUERY(js, 'strict $[*]' WITHOUT WRAPPER) AS "without",
+	JSON_QUERY(js, 'strict $[*]' WITH CONDITIONAL WRAPPER) AS "with cond",
+	JSON_QUERY(js, 'strict $[*]' WITH UNCONDITIONAL ARRAY WRAPPER) AS "with uncond",
+	JSON_QUERY(js, 'strict $[*]' WITH ARRAY WRAPPER) AS "with"
+FROM
+	(VALUES
+		(jsonb '1'),
+		('[]'),
+		('[null]'),
+		('[12.3]'),
+		('[true]'),
+		('["aaa"]'),
+		('[[1, 2, 3]]'),
+		('[{"a": 1, "b": [2]}]'),
+		('[1, "2", null, [3]]')
+	) foo(js);
+
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text KEEP QUOTES);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text KEEP QUOTES ON SCALAR STRING);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING text OMIT QUOTES ON SCALAR STRING);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' OMIT QUOTES ERROR ON ERROR);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING json OMIT QUOTES ERROR ON ERROR);
+SELECT JSON_QUERY(jsonb '"aaa"', '$' RETURNING bytea FORMAT JSON OMIT QUOTES ERROR ON ERROR);
+
+-- QUOTES behavior should not be specified when WITH WRAPPER used:
+-- Should fail
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER OMIT QUOTES);
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH WRAPPER KEEP QUOTES);
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER KEEP QUOTES);
+SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER OMIT QUOTES);
+-- Should succeed
+SELECT JSON_QUERY(jsonb '[1]', '$' WITHOUT WRAPPER OMIT QUOTES);
+SELECT JSON_QUERY(jsonb '[1]', '$' WITHOUT WRAPPER KEEP QUOTES);
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]');
+SELECT JSON_QUERY(jsonb '[]', '$[*]' NULL ON EMPTY);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY ON EMPTY);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY ARRAY ON EMPTY);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' EMPTY OBJECT ON EMPTY);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' DEFAULT '"empty"' ON EMPTY);
+
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY NULL ON ERROR);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY EMPTY ARRAY ON ERROR);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY EMPTY OBJECT ON ERROR);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON EMPTY ERROR ON ERROR);
+SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON ERROR);
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' DEFAULT '"empty"' ON ERROR);
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING json);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING json FORMAT JSON);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING jsonb);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING jsonb FORMAT JSON);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING text);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING char(10));
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING char(3));
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING text FORMAT JSON);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING bytea);
+SELECT JSON_QUERY(jsonb '[1,2]', '$' RETURNING bytea FORMAT JSON);
+
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING bytea EMPTY OBJECT ON ERROR);
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING bytea FORMAT JSON EMPTY OBJECT ON ERROR);
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING json EMPTY OBJECT ON ERROR);
+SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' RETURNING jsonb EMPTY OBJECT ON ERROR);
+
+SELECT
+	x, y,
+	JSON_QUERY(
+		jsonb '[1,2,3,4,5,null]',
+		'$[*] ? (@ >= $x && @ <= $y)'
+		PASSING x AS x, y AS y
+		WITH CONDITIONAL WRAPPER
+		EMPTY ARRAY ON EMPTY
+	) list
+FROM
+	generate_series(0, 4) x,
+	generate_series(0, 4) y;
+
+-- Extension: record types returning
+CREATE TYPE sqljsonb_rec AS (a int, t text, js json, jb jsonb, jsa json[]);
+CREATE TYPE sqljsonb_reca AS (reca sqljsonb_rec[]);
+
+SELECT JSON_QUERY(jsonb '[{"a": 1, "b": "foo", "t": "aaa", "js": [1, "2", {}], "jb": {"x": [1, "2", {}]}},  {"a": 2}]', '$[0]' RETURNING sqljsonb_rec);
+SELECT * FROM unnest((JSON_QUERY(jsonb '{"jsa":  [{"a": 1, "b": ["foo"]}, {"a": 2, "c": {}}, 123]}', '$' RETURNING sqljsonb_rec)).jsa);
+SELECT * FROM unnest((JSON_QUERY(jsonb '{"reca": [{"a": 1, "t": ["foo", []]}, {"a": 2, "jb": [{}, true]}]}', '$' RETURNING sqljsonb_reca)).reca);
+
+-- Extension: array types returning
+SELECT JSON_QUERY(jsonb '[1,2,null,"3"]', '$[*]' RETURNING int[] WITH WRAPPER);
+SELECT * FROM unnest(JSON_QUERY(jsonb '[{"a": 1, "t": ["foo", []]}, {"a": 2, "jb": [{}, true]}]', '$' RETURNING sqljsonb_rec[]));
+
+-- Extension: domain types returning
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.a' RETURNING sqljsonb_int_not_null);
+SELECT JSON_QUERY(jsonb '{"a": 1}', '$.b' RETURNING sqljsonb_int_not_null);
+
+-- Test timestamptz passing and output
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts);
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING json);
+SELECT JSON_QUERY(jsonb 'null', '$ts' PASSING timestamptz '2018-02-21 12:34:56 +10' AS ts RETURNING jsonb);
+
+-- Test constraints
+
+CREATE TABLE test_jsonb_constraints (
+	js text,
+	i int,
+	x jsonb DEFAULT JSON_QUERY(jsonb '[1,2]', '$[*]' WITH WRAPPER)
+	CONSTRAINT test_jsonb_constraint1
+		CHECK (js IS JSON)
+	CONSTRAINT test_jsonb_constraint2
+		CHECK (JSON_EXISTS(js::jsonb, '$.a' PASSING i + 5 AS int, i::text AS txt, array[1,2,3] as arr))
+	CONSTRAINT test_jsonb_constraint3
+		CHECK (JSON_VALUE(js::jsonb, '$.a' RETURNING int DEFAULT ('12' || i)::int ON EMPTY ERROR ON ERROR) > i)
+	CONSTRAINT test_jsonb_constraint4
+		CHECK (JSON_QUERY(js::jsonb, '$.a' WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) < jsonb '[10]')
+	CONSTRAINT test_jsonb_constraint5
+		CHECK (JSON_QUERY(js::jsonb, '$.a' RETURNING char(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) >  'a' COLLATE "C")
+	CONSTRAINT test_jsonb_constraint6
+		CHECK (JSON_EXISTS(js::jsonb, 'strict $.a' RETURNING int TRUE ON ERROR) < 2)
+);
+
+\d test_jsonb_constraints
+
+SELECT check_clause
+FROM information_schema.check_constraints
+WHERE constraint_name LIKE 'test_jsonb_constraint%';
+
+SELECT pg_get_expr(adbin, adrelid) FROM pg_attrdef WHERE adrelid = 'test_jsonb_constraints'::regclass;
+
+INSERT INTO test_jsonb_constraints VALUES ('', 1);
+INSERT INTO test_jsonb_constraints VALUES ('1', 1);
+INSERT INTO test_jsonb_constraints VALUES ('[]');
+INSERT INTO test_jsonb_constraints VALUES ('{"b": 1}', 1);
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 1}', 1);
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 7}', 1);
+INSERT INTO test_jsonb_constraints VALUES ('{"a": 10}', 1);
+
+DROP TABLE test_jsonb_constraints;
+
+-- Test mutabilily od query functions
+CREATE TABLE test_jsonb_mutability(js jsonb);
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a[0]'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime()'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@ < $.datetime())'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime() < $.datetime())'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime() < $.datetime("HH:MI TZH"))'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime("HH:MI TZH") < $.datetime("HH:MI TZH"))'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime("HH:MI") < $.datetime("YY-MM-DD HH:MI"))'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.a ? (@.datetime("HH:MI TZH") < $.datetime("YY-MM-DD HH:MI"))'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime("HH:MI TZH") < $x' PASSING '12:34'::timetz AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime("HH:MI TZH") < $y' PASSING '12:34'::timetz AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime() < $x' PASSING '12:34'::timetz AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime() < $x' PASSING '1234'::int AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime() ? (@ == $x)' PASSING '12:34'::time AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.datetime("YY-MM-DD") ? (@ == $x)' PASSING '2020-07-14'::date AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$[1, $.a ? (@.datetime() == $x)]' PASSING '12:34'::time AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$[1, 0 to $.a ? (@.datetime() == $x)]' PASSING '12:34'::time AS x));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$[1, $.a ? (@.datetime("HH:MI") == $x)]' PASSING '12:34'::time AS x));
+DROP TABLE test_jsonb_mutability;
-- 
2.25.4

