Hi,
is the empty array representable in PostgreSQL, and is it
distinguishable from NULL?
oocms=# SELECT ARRAY[1, 2];array
-------{1,2}
(1 запись)
oocms=# SELECT '{1, 2}'::INT[];int4
-------{1,2}
(1 запись)
oocms=# SELECT ARRAY[];
ERROR: syntax error at or near "]" at character 14
oocms=# SELECT '{}'::INT[];int4
------{}
(1 запись)
oocms=# SELECT ARRAY(SELECT 1 UNION SELECT 2);?column?
----------{1,2}
(1 запись)
oocms=# SELECT ARRAY(SELECT 1 WHERE FALSE);?column?
----------
(1 запись)
--
Markus Bertheau <twanger@bluetwanger.de>
