SQL SERVER常用取重複記錄的SQL語句

1. 擷取某欄位或幾個欄位有重複的資料，可限定重複幾條
   select field1,field2 from table group by field1,field2 having count(field1)>1
2. 擷取某欄位不重複的最新記錄
   select top * from table a where id in(select max(id) from table b group by field) order by id desc
3. 擷取某欄位的重複數
   select count(field) from table group by field having count(field)>1
4. 擷取不重複的記錄
   select field1,field2 from table group by field1,field2
5. 重複資料刪除記錄
   delete from from table a where id not in(select max(id) from table b group by field)