sqlserver 查询重复数据

 use StudentManageDB
 go
 insert into ScoreList (StudentId,CSharp,SQLServerDB)values(100006,52,80)
 insert into ScoreList (StudentId,CSharp,SQLServerDB)values(100007,91,66)
 insert into ScoreList (StudentId,CSharp,SQLServerDB)values(100009,78,35)

 select * from ScoreList order by StudentId

 --在知道那个字段重复的情况
 select StudentId from ScoreList  group by StudentId having COUNT(*)>1

 --查询所有重复的记录
 select * from ScoreList
 where StudentId in(select StudentId from ScoreList  group by StudentId having COUNT(*)>1)
 order by StudentId

 --其他方法
 select * from ScoreList
 where (select COUNT(*) from ScoreList  s where s.StudentId=ScoreList.StudentId)>1
 order by StudentId

 --过滤掉重复数据
 select distinct StudentId,CSharp from ScoreList

 select distinct StudentId,CSharp,SQLServerDB from ScoreList