drop database if exists - Mailing list pgsql-patches

here's a patch for "drop database if exists". Barring objections I will
apply it in a day or two.

cheers

andrew


Index: doc/src/sgml/ref/drop_database.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/ref/drop_database.sgml,v
retrieving revision 1.20
diff -c -r1.20 drop_database.sgml
*** doc/src/sgml/ref/drop_database.sgml    21 Jun 2005 04:02:31 -0000    1.20
--- doc/src/sgml/ref/drop_database.sgml    21 Nov 2005 13:39:55 -0000
***************
*** 20,26 ****

   <refsynopsisdiv>
  <synopsis>
! DROP DATABASE <replaceable class="PARAMETER">name</replaceable>
  </synopsis>
   </refsynopsisdiv>

--- 20,26 ----

   <refsynopsisdiv>
  <synopsis>
! DROP DATABASE [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable>
  </synopsis>
   </refsynopsisdiv>

***************
*** 46,51 ****
--- 46,61 ----

    <variablelist>
     <varlistentry>
+     <term><literal>IF EXISTS</literal></term>
+     <listitem>
+      <para>
+       Do not throw an error if the database does not exist. A notice is issued
+       in this case.
+      </para>
+     </listitem>
+    </varlistentry>
+
+    <varlistentry>
      <term><replaceable class="PARAMETER">name</replaceable></term>
      <listitem>
       <para>
Index: src/backend/commands/dbcommands.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v
retrieving revision 1.173
diff -c -r1.173 dbcommands.c
*** src/backend/commands/dbcommands.c    15 Oct 2005 02:49:15 -0000    1.173
--- src/backend/commands/dbcommands.c    21 Nov 2005 13:39:55 -0000
***************
*** 551,557 ****
   * DROP DATABASE
   */
  void
! dropdb(const char *dbname)
  {
      Oid            db_id;
      bool        db_istemplate;
--- 551,557 ----
   * DROP DATABASE
   */
  void
! dropdb(const char *dbname, bool missing_ok)
  {
      Oid            db_id;
      bool        db_istemplate;
***************
*** 585,593 ****

      if (!get_db_info(dbname, &db_id, NULL, NULL,
                       &db_istemplate, NULL, NULL, NULL, NULL, NULL))
!         ereport(ERROR,
                  (errcode(ERRCODE_UNDEFINED_DATABASE),
                   errmsg("database \"%s\" does not exist", dbname)));

      if (!pg_database_ownercheck(db_id, GetUserId()))
          aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
--- 585,609 ----

      if (!get_db_info(dbname, &db_id, NULL, NULL,
                       &db_istemplate, NULL, NULL, NULL, NULL, NULL))
!     {
!         if (! missing_ok)
!         {
!             ereport(ERROR,
                  (errcode(ERRCODE_UNDEFINED_DATABASE),
                   errmsg("database \"%s\" does not exist", dbname)));
+         }
+         else
+         {
+
+             /* Close pg_database, release the lock, since we changed nothing */
+             heap_close(pgdbrel, ExclusiveLock);
+             ereport(NOTICE,
+                     (errmsg("database \"%s\" does not exist, skipping",
+                             dbname)));
+
+             return;
+         }
+     }

      if (!pg_database_ownercheck(db_id, GetUserId()))
          aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
Index: src/backend/parser/gram.y
===================================================================
RCS file: /cvsroot/pgsql/src/backend/parser/gram.y,v
retrieving revision 2.514
diff -c -r2.514 gram.y
*** src/backend/parser/gram.y    21 Nov 2005 12:49:31 -0000    2.514
--- src/backend/parser/gram.y    21 Nov 2005 13:40:01 -0000
***************
*** 4698,4704 ****

  /*****************************************************************************
   *
!  *        DROP DATABASE
   *
   * This is implicitly CASCADE, no need for drop behavior
   *****************************************************************************/
--- 4698,4704 ----

  /*****************************************************************************
   *
!  *        DROP DATABASE [ IF EXISTS ]
   *
   * This is implicitly CASCADE, no need for drop behavior
   *****************************************************************************/
***************
*** 4707,4712 ****
--- 4707,4720 ----
                  {
                      DropdbStmt *n = makeNode(DropdbStmt);
                      n->dbname = $3;
+                     n->missing_ok = FALSE;
+                     $$ = (Node *)n;
+                 }
+             | DROP DATABASE IF_P EXISTS database_name
+                 {
+                     DropdbStmt *n = makeNode(DropdbStmt);
+                     n->dbname = $5;
+                     n->missing_ok = TRUE;
                      $$ = (Node *)n;
                  }
          ;
Index: src/backend/tcop/utility.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/tcop/utility.c,v
retrieving revision 1.247
diff -c -r1.247 utility.c
*** src/backend/tcop/utility.c    21 Nov 2005 12:49:32 -0000    1.247
--- src/backend/tcop/utility.c    21 Nov 2005 13:40:02 -0000
***************
*** 840,846 ****
              {
                  DropdbStmt *stmt = (DropdbStmt *) parsetree;

!                 dropdb(stmt->dbname);
              }
              break;

--- 840,846 ----
              {
                  DropdbStmt *stmt = (DropdbStmt *) parsetree;

!                 dropdb(stmt->dbname, stmt->missing_ok);
              }
              break;

Index: src/include/commands/dbcommands.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/commands/dbcommands.h,v
retrieving revision 1.42
diff -c -r1.42 dbcommands.h
*** src/include/commands/dbcommands.h    15 Oct 2005 02:49:44 -0000    1.42
--- src/include/commands/dbcommands.h    21 Nov 2005 13:40:03 -0000
***************
*** 53,59 ****
  } xl_dbase_drop_rec;

  extern void createdb(const CreatedbStmt *stmt);
! extern void dropdb(const char *dbname);
  extern void RenameDatabase(const char *oldname, const char *newname);
  extern void AlterDatabase(AlterDatabaseStmt *stmt);
  extern void AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
--- 53,59 ----
  } xl_dbase_drop_rec;

  extern void createdb(const CreatedbStmt *stmt);
! extern void dropdb(const char *dbname, bool missing_ok);
  extern void RenameDatabase(const char *oldname, const char *newname);
  extern void AlterDatabase(AlterDatabaseStmt *stmt);
  extern void AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
Index: src/include/nodes/parsenodes.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/nodes/parsenodes.h,v
retrieving revision 1.294
diff -c -r1.294 parsenodes.h
*** src/include/nodes/parsenodes.h    21 Nov 2005 12:49:32 -0000    1.294
--- src/include/nodes/parsenodes.h    21 Nov 2005 13:40:04 -0000
***************
*** 1672,1677 ****
--- 1672,1678 ----
  {
      NodeTag        type;
      char       *dbname;            /* database to drop */
+     bool        missing_ok;     /* skip error if db is missing? */
  } DropdbStmt;

  /* ----------------------