查询一:
SELECT ARRAY(select id from contacts where id = 0)::INT[],
ARRAY[]::INT[],
ARRAY(SELECT id FROM contacts WHERE id = 0)::INT[] = ARRAY[]::int[]
产生这个结果:
int4 array ?column?
{} {} TRUE
查询 2:
SELECT (ARRAY(SELECT id FROM contacts WHERE id = 0)::INT[]
& ARRAY(select id from contacts where id = 0)::INT[]),
ARRAY[]::INT[],
(ARRAY(SELECT id FROM contacts WHERE id = 0)::INT[]
& ARRAY(SELECT id FROM contacts WHERE id = 0)::INT[]) = ARRAY[]::int[]
产生不同的结果:
?column? array ?column?
{} {} FALSE
为什么有区别?
有没有其他方法可以将空整数数组与第二个查询中的两个数组相交的结果进行比较?