SQL SERVER常用取重复记录的SQL语句

1. 获取某字段或几个字段有重复的数据，可限定重复几条
   select field1,field2 from table group by field1,field2 having count(field1)>1
2. 获取某字段不重复的最新记录
   select top * from table a where id in(select max(id) from table b group by field) order by id desc
3. 获取某字段的重复数
   select count(field) from table group by field having count(field)>1
4. 获取不重复的记录
   select field1,field2 from table group by field1,field2
5. 删除重复记录
   delete from from table a where id not in(select max(id) from table b group by field)