Posted on 2015-03-12 13:53
朱杰兵 阅读(88)
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两张关联表，删除主表中已经在副表中没有的信息delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )
删除重复记录delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)