SQLServer去重复数据

删除表中多余的重复记录，重复记录是根据单个字段（seasonId ）来判断，只留有rowid最小的记录

分析： 

select seasonId ,count(1) FROM [HD_GameData].[dbo].[LZ_Season_List] group by seasonId  having count(1)>1 order by seasonId

 select min(id)  FROM [HD_GameData].[dbo].[LZ_Season_List] group by seasonId  having count(1)>1  order by seasonId

执行SQL

 delete from [HD_GameData].[dbo].[LZ_Season_List] where seasonId

 in ( select seasonId  FROM [HD_GameData].[dbo].[LZ_Season_List] group by seasonId  having count(1)>1 )

 and

 id not in (  select min(id)  FROM [HD_GameData].[dbo].[LZ_Season_List] group by seasonId  having count(1)>1)

查找表中多余的重复记录（多个字段,seasonId ,sportId ）

select seasonId ,sportId FROM [HD_GameData].[dbo].[LZ_Season_List] group by seasonId,sportId   having count(1)>1 order by seasonId

 select min(id)  FROM [HD_GameData].[dbo].[LZ_Season_List] group by seasonId, sportId having count(1)>1  order by seasonId

执行SQL:

 delete from [HD_GameData].[dbo].[LZ_Season_List] where (seasonId,sportId)

 in ( select seasonId ,sportId FROM [HD_GameData].[dbo].[LZ_Season_List] group by seasonId,sportId   having count(1)>1 )

 and

 id not in (  select min(id)  FROM [HD_GameData].[dbo].[LZ_Season_List] group by seasonId,sportId     having count(1)>1)