Question

SELECT u.name, u.age, u.sex
FROM User u
INNER JOIN (
SELECT age, sex, COUNT(*)
FROM User
GROUP BY age, sex
HAVING COUNT(*) > 1) temp
ON temp.age = u.age
AND temp.sex = u.sex
ORDER BY age, sex

此查询在数据库中找到我所有的重复项，但是如何删除多个重复项？

Answer 1

选择您仅选择的行中的ID，然后放入DELETE，这将删除所有已选择ID的行。

DELETE FROM User u
WHERE u.ID IN
(
    SELECT u.ID
    FROM User u
    INNER JOIN
    (
        SELECT u.ID
        FROM User
        GROUP BY age, sex
        HAVING COUNT(*) > 1
    ) temp
    ON temp.age = u.age
    AND temp.sex = u.sex
    ORDER BY age, sex
)

但是我必须建议您更改查询，因为它会删除所有内容。如果内部连接，则select语句与SELECT * FROM User相同。所以我想您真正想要的是：

DELETE FROM User u
WHERE u.ID IN
(
    SELECT u.ID
    FROM User
    GROUP BY age, sex
    HAVING COUNT(*) > 1
)

如何删除mysql查询找到的条目？

1 个答案: