求一sql语句

[blue_snow]

我想把一个表的三个字段a,b,c加为主键，但是里面有重复数据（即三个字段的值都一样）我怎么查出那些记录来呢？

[qdubit]

select a,b,c from 表 group by a,b,c having count(*)>1

[lynx1111]

都是对的，楼主自己好好测一下

[txlicenhe]

Select a,b,c from 表 group by a,b,c having count(*) > 1

[pengdali]

select * from 表 tem where exists(
Select 1 from 表 group by a,b,c having count(*) > 1 and a=tem.a and b=tem.b and c=tem.c)

[blue_snow]

to 马可
按照你的方法还是查不出有哪些记录是重复的呀

[welyngj]

select * from tbl a where exists ( select a,b,c from tbl b where a.a=b.a
and a.b=b.b and a.c=b.c group by a,b,c having count(a)>1 )

[lijinqiang]

pengdali(大力 V3.0)能达到效果

[blue_snow]

to 大力
你的语句效果是一样的，我只想查出那些三个字段都一样的记录

[pengdali]

Select * from 表 where a=b and a=c


??

[银狐被占用]

select a,b,c from 表 group by a,b,c having count(*)>1

[guangli_zhang]

select * from table1 aa where (select count(*) from table1 bb where b.aa = a.aa and b.bb = a.bb and b.cc = a.cc) >= 2

[guangli_zhang]

对不起,写错了
select * from table1 aa where (select count(*) from table1 bb where bb.a = aa.a and bb.b = aa.b and bb.c = aa.c) >= 2

[xjwxiong]

select a,b,c,sum(d) as d from (select a,b,c,1 as d from table1)A
where d>1
group by a,b,c

[yonghengdizhen]

Select * from tablename ta where (select count(*) from tablename where a=ta.a and b.ta.b and c=ta.c)>1

[blue_snow]

我想问一下：select * from 表 tem where exists(
Select 1 from 表 group by a,b,c having count(*) > 1 and a=tem.a and b=tem.b and c=tem.c)中，select 1 是什么意思，有些看不懂

[yonghengdizhen]

to blue_snow(因为所以)
存在性判断你管它输出什么干吗?

[xcloudky]

去网上找！