我必须在Postgresql的另一个Select
中执行此查询:
SELECT COUNT(tn.autoship_box_transaction_id)
FROM memberships.autoship_box_transaction tn
WHERE tn.autoship_box_id = b.autoship_box_id
我必须使用
WITH
子句吗?我必须在Postgresql的另一个Select
中执行此查询:
SELECT COUNT(tn.autoship_box_transaction_id)
FROM memberships.autoship_box_transaction tn
WHERE tn.autoship_box_id = b.autoship_box_id
WITH
子句吗?SELECT (
SELECT COUNT(tn.autoship_box_transaction_id)
FROM memberships.autoship_box_transaction tn
WHERE tn.autoship_box_id = b.autoship_box_id
) AS cnt
, other_column
FROM wherever
;
b
。from
子句的选项(请注意:警惕:此语句仅用于说明目的;您必须根据自己的用例进行调整,我只是猜测)。SELECT stats.cnt
, b.other_column
FROM b_table b
JOIN (
SELECT COUNT(tn.autoship_box_transaction_id) cnt
, tn.autoship_box_id
FROM memberships.autoship_box_transaction tn
GROUP BY tn.autoship_box_id
) stats
ON (stats.autoship_box_id = b.autoship_box_id)
;
with
子句,像这样:
WITH some_count AS (
SELECT COUNT(tn.autoship_box_transaction_id)
FROM memberships.autoship_box_transaction tn
WHERE tn.autoship_box_id = b.autoship_box_id
)
SELECT * FROM some_count;
第二个选项是使用子查询,像这样:
SELECT
*
FROM
(
SELECT COUNT(tn.autoship_box_transaction_id)
FROM memberships.autoship_box_transaction tn
WHERE tn.autoship_box_id = b.autoship_box_id
);