create table Test(Nos int,Data varchar)
insert into Test values(1,'A'),(2,'B'),(2,'C'),(3,'D'),(4,'D'),(4,'D'),(5,'E')
select * from Test
--Query to delete duplicate records
;with dup as
(
select *,ROW_NUMBER()over(partition by Nos,Data order by Nos,Data)DupNo from Test
)delete from dup where DupNo>1
select * from Test