sql字段查重

select * from shiyan003 a where exists (select 1 from (select xm, sfzhm from shiyan003 group by xm, sfzhm having count(*) > 1) s where xm = xm and sfzhm = sfzhm)

查询重复数据，方法如下：select * from [表A] where id in (select id from [表A] group by id having count(id) >1 )

应该是in关键字不支持多字段吧，你这样试一下select *  from shiyan003 a where exists (select 1          from (select xm, sfzhm                  from shiyan003                 group by xm, sfzhm                having count(*) > 1) s         where xm = xm           and sfzhm = sfzhm)

select * from shiyan003 awhere xm in (select xm from shiyan003 group by xm,sfzhm having count(*) > 1)and sfzhm in (select sfzhm from shiyan003 group by xm,sfzhm having count(*) > 1)原句的错在in的使用上

SELECT *, count(*) AS CCCFROM 表明GROUP BY 字段ORDER BY CCC DESC

selectid,name,memofromAwhereidin(selectidfromAgroupbyidhavingcount(1)>=2)1查询 abcd相同的记录：select * from F where a=b and b=c and c=d2查询有重复数据的记录select * from F group by a,b,c,d having count(*)>13取出数据过滤到重复的数据select distinct a,b,c,d from f