Question

有一个名为user_products的表，其中包含用户已获得许可的每个产品的记录。

user_id，product_id，（其他一些字段，如时间戳）

我有18个产品，但想找到所有拥有产品3记录和产品4记录的用户，然后删除他们对产品3的记录。

Answer 1

DELETE 
FROM user_products AS up3
WHERE product_id = 3
  AND EXISTS 
      ( SELECT *
        FROM user_products AS up4
        WHERE up4.product_id = 4
          AND up4.user_id = up3.user_id
      )

或JOIN：

DELETE up3
FROM user_products AS up3
  JOIN user_products AS up4
    ON up4.user_id = up3.user_id
WHERE up3.product_id = 3
  AND up4.product_id = 4

在mySQL中删除具有多个产品记录的用户

1 个答案: