Question

我有子查询的多个IN条件。

SELECT
    S.name,
    S.email
FROM something S
WHERE 
    1 NOT IN (SELECT id FROM tags WHERE somethingId = S.id)
    AND 2 NOT IN (SELECT id FROM tags WHERE somethingId = S.id)
    AND 3 NOT IN (SELECT id FROM tags WHERE somethingId = S.id)

也许有更好的解决方案？类似的东西：

    (1, 2, 3) NOT IN (SELECT id FROM tags WHERE somethingId = S.id)

Answer 1

重写以改为使用NOT EXISTS。即，当标签中没有行，其中等于s.id并且id为1,2或3时，从S返回。

SELECT
    S.name,
    S.email
FROM something S
WHERE NOT EXISTS (SELECT 1 FROM tags WHERE id in (1, 2, 3) and somethingId = S.id)

NOT EXISTS也是“无效的”。（NOT IN (select returning a null)根本不会返回任何行。）

MySQL多个IN条件与子表相同的表

1 个答案: