MySQL使用子查询作为delete或update的条件

update和delete的使用方式一样，下面以delete示例

1、如果delete(update)使用的表和子查询的表不是同一张表，直接使用子查询结果即可:

delete from table_1
    where id = (
        select id
        from table_2
        where create_date = '2020-06-28'
    　　limit 1
);

2、如果是同一张表，像上面一样直接使用子查询结果会出错

delete from table_1
    where id = (
        select id
        from table_1
        where create_date = '2020-06-28'
        limit 1
);

会报错：[Err] 1093 - You can't specify target table 'trade_order' for update in FROM clause，意思是不能对同一张表同时使用select和删改语句，因此需要使用到临时表

delete from table_1
where id = (select id from 
         (select id
          from table_1
          where create_date = '2020-06-28'
          limit 1
          ) a1
); 

就能成功执行了

ps: 如果需要给delete使用的表起个别名，则需要这样写

delete a2 from table_1 a2
where id = (select id from 
         (select id
          from table_1
          where create_date = '2020-06-28'
          limit 1
          ) a1
);