Question

MySQL 为什么不允许delete语句使用表别名

Answer 1

可以用别名，只是你写法写错了。
DELETE t1 FROM test AS t1 WHERE .....

参见 http://dev.mysql.com/doc/refman/5.7/en/delete.html

Answer 2

有一个表的数据比较大，然后需要进行关联删除，删除的时候发现如下SQL报错：

DELETE FROM test.test1 a WHERE EXISTS (SELECT 1 FROM test.test2 b WHERE a.recordID=b.smsInfoID AND b.receiveTime <="2011-10-09 00:00:00" ) limit 1000;

报错如下：

Error Code: 1064
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'a WHERE EXISTS (SELECT 1 FROM test.test2 b WHERE a.recordID=b.smsInf' at line 1 www.2cto.com
开始以为是exists的问题，于是更改成in再测试，也报同样错：

DELETE FROM test.test1 a WHERE a.recordid IN (SELECT b.smsInfoID FROM test.test2 b WHERE b.receiveTime <= "2011-10-09 00:00:00") LIMIT 1000;

原来是MYSQL的delete语句不支持别名！

将别名去掉就可以了，将上面两个报错的SQL更改成如下形式就可以了：

DELETE FROM test.test1 WHERE recordid IN (SELECT smsInfoID FROM test.test2 WHERE receiveTime <= "2011-10-09 00:00:00") LIMIT 1000; www.2cto.com
DELETE FROM test.test1 WHERE EXISTS (SELECT 1 FROM test.test2 WHERE test1.recordID=test2.smsInfoID AND test2.receiveTime <= "2011-10-09 00:00:00") LIMIT 1000;

转自：http://www.2cto.com/database/201204/127360.html

Answer 3

你在什么情况下使用别名，删除时应该用不到别名吧

追问

1. 我个人习惯在表操作的时候给表起别名
   

2. 我就是好奇为啥mysql 规定delete语句不能起别名，十分好奇
   

追答

这个回答不了，对不起……