SQL用select语句查询重复记录
SQL用select语句查询重复记录
http://hi.baidu.com/bilbit/blog/item/5ed5de16a6f6b412962b43eb.html
用select语句,查询重复记录
假设,表名为 T1 子段为 A,B,C
select count(*) ,A,B,C from T1
group by A,B,C having count(*) > 1
测试数据:
A100 B100 C100
A101 B101 C101
A102 B102 C102
A102 B102 C100
A102 B102 C102
A102 B102 C102
A100 B100 C100
运行结果:
2 A100 B100 C100
3 A102 B102 C102
========================================================
选择重复,消除重复和选择出序列
有例表:emp
emp_no name age &nbs
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SQL查询重复记录
http://m.cnblogs.com/15628/1534873.html
1、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断
[图片]select * from people
[图片]where peopleId in (select peopleId from people group by peopleId ......