SQL Server 2005's new added Ranking functions

Ranking functions return a ranking value for each row in a partition. Depending on the function that is used, some rows might receive the same value as other rows. Ranking functions are nondeterministic.

Transact-SQL provides the following ranking functions:

RANK	NTILE
DENSE_RANK	ROW_NUMBER

Examples

The following shows the four ranking functions used in the same query. For function specific examples, see each ranking function.

USE AdventureWorks2008R2;
GO
SELECT p.FirstName, p.LastName
   ,ROW_NUMBER() OVER (ORDER BY a.PostalCode) AS 'Row Number'
   ,RANK() OVER (ORDER BY a.PostalCode) AS 'Rank'
   ,DENSE_RANK() OVER (ORDER BY a.PostalCode) AS 'Dense Rank'
   ,NTILE(4) OVER (ORDER BY a.PostalCode) AS 'Quartile'
   ,s.SalesYTD, a.PostalCode
FROM Sales.SalesPerson s
   INNER JOIN Person.Person p
       ON s.BusinessEntityID = p.BusinessEntityID
   INNER JOIN Person.Address a
       ON a.AddressID = p.BusinessEntityID
WHERE TerritoryID IS NOT NULL
   AND SalesYTD <> 0;

Here is the result set.

FirstName	LastName	Row Number	Rank	Dense Rank	Quartile	SalesYTD	PostalCode
Michael	Blythe	1	1	1	1	4557045.0459	98027
Linda	Mitchell	2	1	1	1	5200475.2313	98027
Jillian	Carson	3	1	1	1	3857163.6332	98027
Garrett	Vargas	4	1	1	1	1764938.9859	98027
Tsvi	Reiter	5	1	1	2	2811012.7151	98027
Shu	Ito	6	6	2	2	3018725.4858	98055
José	Saraiva	7	6	2	2	3189356.2465	98055
David	Campbell	8	6	2	3	3587378.4257	98055
Tete	Mensa-Annan	9	6	2	3	1931620.1835	98055
Lynn	Tsoflias	10	6	2	3	1758385.926	98055
Rachel	Valdez	11	6	2	4	2241204.0424	98055
Jae	Pak	12	6	2	4	5015682.3752	98055
Ranjit	Varkey Chudukatil	13	6	2	4	3827950.238	98055