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  • mysql delete别名

    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:
    ELETE 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
    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;
    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;
    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;

    通过网友的指点,发现可以通过别名删除,只是语法有点奇怪,下面支持别名的语法:
    DELETE test.a 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;

    原文(http://blog.chinaunix.net/uid/122369.html)

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  • 原文地址:https://www.cnblogs.com/gavinYang/p/11197871.html
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