排名函数 (Transact-SQL)
排名函数为分区中的每一行返回一个排名值。根据所用函数的不同,某些行可能与其他行接收到相同的值。排名函数具有不确定性。
Transact-SQL 提供下列排名函数:
示例
以下示例显示了用在同一查询中的四个排名函数。有关每个函数的具体示例,请参阅每个排名函数。
USE AdventureWorks;
GO
SELECT c.FirstName, c.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.Contact c
ON s.SalesPersonID = c.ContactID
INNER JOIN Person.Address a
ON a.AddressID = c.ContactID
WHERE TerritoryID IS NOT NULL
AND SalesYTD <> 0;
下面是结果集。
FirstName |
LastName |
Row Number |
Rank |
Dense Rank |
Quartile |
SalesYTD |
PostalCode |
---|---|---|---|---|---|---|---|
Maciej |
Dusza |
1 |
1 |
1 |
1 |
4557045 |
98027 |
Shelley |
Dyck |
2 |
1 |
1 |
1 |
5200475 |
98027 |
Linda |
Ecoffey |
3 |
1 |
1 |
1 |
3857164 |
98027 |
Carla |
Eldridge |
4 |
1 |
1 |
1 |
1764939 |
98027 |
Carol |
Elliott |
5 |
1 |
1 |
2 |
2811013 |
98027 |
Jauna |
Elson |
6 |
6 |
2 |
2 |
3018725 |
98055 |
Michael |
Emanuel |
7 |
6 |
2 |
2 |
3189356 |
98055 |
Terry |
Eminhizer |
8 |
6 |
2 |
3 |
3587378 |
98055 |
Gail |
Erickson |
9 |
6 |
2 |
3 |
5015682 |
98055 |
Mark |
Erickson |
10 |
6 |
2 |
3 |
3827950 |
98055 |
Martha |
Espinoza |
11 |
6 |
2 |
4 |
1931620 |
98055 |
Janeth |
Esteves |
12 |
6 |
2 |
4 |
2241204 |
98055 |
Twanna |
Evans |
13 |
6 |
2 |
4 |
1758386 |
98055 |