技術標籤：PostgreSQL 13.0 Documentationpostgresql

SELECT * FROM sal_emp WHERE pay_by_quarter[1] = 10000 OR
pay_by_quarter[2] = 10000 OR
pay_by_quarter[3] = 10000 OR
pay_by_quarter[4] = 10000;
 

However, this quickly becomes tedious for large arrays, and is not helpful if the size of the array isunknown. An alternative method is described in Section 9.23. The above query could be replaced by:

SELECT * FROM sal_emp WHERE 10000 = ANY (pay_by_quarter);
 

In addition, you can find rows where the array has all values equal to 10000 with:

SELECT * FROM sal_emp WHERE 10000 = ALL (pay_by_quarter);

Alternatively, the generate_subscripts function can be used. For example:

SELECT * FROM
(SELECT pay_by_quarter,
generate_subscripts(pay_by_quarter, 1) AS s
FROM sal_emp) AS foo
WHERE pay_by_quarter[s] = 10000;
 

SELECT * FROM sal_emp WHERE pay_by_quarter && ARRAY[10000];

This and other array operators are further described in Section 9.18. It can be accelerated by an appropriateindex, as described in Section 11.2.

SELECT
array_position(ARRAY['sun','mon','tue','wed','thu','fri','sat'],
'mon');
array_positions
-----------------
2
SELECT array_positions(ARRAY[1, 4, 3, 1, 3, 4, 2, 1], 1);
array_positions
-----------------
{1,4,8}