The following bug has been logged on the website:
Bug reference: 18632
Logged by: Man Zeng
Email address: zengman@halodbtech.com
PostgreSQL version: 14.10
Operating system: centos-8
Description:
Hi, I found a problem with array separator handling.
The current handling of delimiters is not quite as expected (not very
flexible).
The test SQL and results are shown below.
[postgres@halo-centos-8-release ~]$ psql
psql (14.10)
Type "help" for help.
postgres=# CREATE OR REPLACE FUNCTION arrayfunc()
postgres-# RETURNS _varchar
postgres-# AS $$
postgres$# SELECT '{''a,3'',''b'',''c''}'::_varchar;
postgres$# $$ LANGUAGE SQL;
CREATE FUNCTION
postgres=# -- array cstring
postgres=# SELECT arrayfunc();
arrayfunc
-----------------
{'a,3','b','c'}
(1 row)
postgres=# -- length is 4
postgres=# SELECT array_length(arrayfunc(), 1);
array_length
--------------
4
(1 row)
postgres=# -- first element
postgres=# SELECT (arrayfunc())[1];
arrayfunc
-----------
'a
(1 row)
postgres=# -- second element
postgres=# SELECT (arrayfunc())[2];
arrayfunc
-----------
3'
(1 row)
postgres=# -- other
postgres=# SELECT (arrayfunc())[3];
arrayfunc
-----------
'b'
(1 row)
postgres=# SELECT (arrayfunc())[4];
arrayfunc
-----------
'c'
(1 row)
postgres=# -- The following SQL tests are as expected
postgres=# CREATE OR REPLACE FUNCTION arrayfunc2()
postgres-# RETURNS _varchar
postgres-# AS $$
postgres$# SELECT '{''a-3'',''b'',''c''}'::_varchar;
postgres$# $$ LANGUAGE SQL;
CREATE FUNCTION
postgres=# -- array cstring
postgres=# SELECT arrayfunc2();
arrayfunc2
-----------------
{'a-3','b','c'}
(1 row)
postgres=# -- length is 3
postgres=# SELECT array_length(arrayfunc2(), 1);
array_length
--------------
3
(1 row)
postgres=# -- first element
postgres=# SELECT (arrayfunc2())[1];
arrayfunc2
------------
'a-3'
(1 row)
So should we consider modifying "array_in" to enhance the handling of
separators to be more consistent with people's expectations?