[b]1、查找重复记录 [/b]①如果只是不想在查询结果中存在重复记录, 可以加Distinct select distinct * from TestTable [b]②如果是想查询重复的记录及其数量[/b] select UserID,UserName,count(*) as '记录数' from TestTable Group by UserID,UserName having count(*)>1 [b]③ID不重复, 但是字段重复的记录只显示一条[/b] select * from TestTable where UserID in (select max(UserID) as UserID from TestTable group by UserName,Sex,Place) 2、删除重复记录 ①一种思路是利用临时表, 把查询到的无重复记录填充到临时表, 再把临时表的记录填充回原始表 select distinct * into #Temp from TestTable drop table TestTable select * into TestTable from #Temp drop table #Temp ②删除ID不重复, 但是字段重复的记录(就是按字段查询出相同字段记录中最大的ID,然后保留此记录, 删除其他记录).(group by 的字段, 有点麻烦). delete TestTable where UserID not in (select max(UserID) as UserID from TestTable group by UserName,Sex,Place)