Posted on 2015-03-12 13:53
朱杰兵 閱讀(91)
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兩張關聯(lián)表，刪除主表中已經(jīng)在副表中沒有的信息delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )
刪除重復記錄delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)