Ranking Functions In SQL Server

ROW_NUMBER ()

Row number returns continues number of row  with in a partition, starting at 1 for 1^st Row

RANK ()

Ranking the each row with in the partition ,chance for gap depending partition 

DENSE_RANK ()

Ranking the each row with in the partition without any gaps, means  continues ranking

NTILE()

Ranking the total records in a specific number of groups

CREATE TABLE TEST (NAME VARCHAR(20),MARK INT)

INSERT INTO TEST VALUES('RAM',10)

INSERT INTO TEST VALUES('RAJU',10)

INSERT INTO TEST VALUES('VINEETH',10)

INSERT INTO TEST VALUES('RANITH',50)

INSERT INTO TEST VALUES('TELMI',50)

INSERT INTO TEST VALUES('JHON',100)

 SELECT

 ROW_NUMBER() OVER (ORDER BY MARK) AS 'SLNO',

 RANK() OVER (ORDER BY MARK) AS 'RANK',

 DENSE_RANK() OVER (ORDER BY MARK) AS 'DENSE RANK',

 NTILE(2) OVER (ORDER BY MARK) AS 'NTILE'

 ,NAME,MARK

 FROM TEST

 OUT PUT