报错的SQL为:
delete from message where id not in (select min(id) as id from message group by content);
报错信息的中文意思为:不能在FROM子句中更新 message表数据,原因是 "不能在从本表中查出数据范围后,然后直接更新本表",
解决方法思路是,让数据库认为,你查出的数据范围,是不从本表中查出来的,实现步骤如下:
1、用as,给查出的数据表,设置别名为a,即 (select min(id) as id from message group by content)as a
2、用别名,查出数据范围,即 select a.id from (select min(id) as id from message group by content)as a
修改后的完整SQL为
delete from message where id not in (select a.id from (select min(id) as id from message group by content) as a);
Mysql更新数据时,报 “You can't specify target table 'message ' for update in FROM clause” 解决办法
原文地址:https://www.cnblogs.com/testeyes/p/11419188.html
时间: 2024-10-18 15:26:49