哥们,你试过吗?其实cyt的答案,我最喜欢,性能最好, 两者并无不同。还可以:select * from T t1 where exists(select 1 from t t2 where t1.a=t2.a having count(0)>1);

onewayticket (onewayticket)
2001-11-14 -04:00
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Back To Topic: 闲来无事, 出道ORACLE SQL的题考考大家. 这是在下几个月前工作中遇到的问题, 看似简单, 其实不然.

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