mysql删除查询，子查询不起作用

Question

我尝试创建 mysql 事件，该事件应删除重复的表行。

这是我的查询

DELETE FROM locations
WHERE id NOT IN (SELECT  id
                 FROM locations
                 GROUP BY acc_id,`date`)

我收到了这个错误：

Error Code: 1093
You can't specify target table 'locations' for update in FROM clause.

如何更改查询以使其正常工作？

Answer 1

在MySQL中，您无法从您选择的同一个表中删除。但是你可以用另一个子选项来欺骗MySQL

DELETE FROM locations
WHERE id NOT IN 
(
  select * from 
  (
      SELECT id
      FROM locations
      GROUP BY acc_id, `date`
  ) x
)

Answer 2

尝试在子查询中提供自定义别名，不能在update / delete中直接指定相同的表

DELETE FROM locations
WHERE id NOT IN (
SELECT new_table.id FROM (
SELECT  id
FROM locations
GROUP BY acc_id,`date`
) new_table    
)