Sql中Rank排名函数

A.对分区中的行进行排名

以下示例按照数量对指定清单位置的清单中的产品进行了排名。

结果集按 LocationID 分区并在逻辑上按 Quantity 排序。

注意，产品 494 和 495 具有相同的数量。 因为它们是关联的，所以两者均排名第一。

USE AdventureWorks2012;
GO
SELECT i.ProductID, p.Name, i.LocationID, i.Quantity ,RANK() OVER  (PARTITION BY i.LocationID ORDER BY i.Quantity DESC) AS Rank
FROM Production.ProductInventory AS i
INNER JOIN Production.Product AS p  ON i.ProductID = p.ProductID
WHERE i.LocationID BETWEEN 3 AND 4
ORDER BY i.LocationID;
GO

下面是结果集：

ProductID   Name                   LocationID   Quantity Rank
----------- ---------------------- ------------ -------- ----
494         Paint - Silver                3            49       1
495         Paint - Blue                  3            49       1
493         Paint - Red                   3            41       3
496         Paint - Yellow              3            30       4
492         Paint - Black                 3            17       5
495         Paint - Blue                  4            35       1
496         Paint - Yellow              4            25       2
493         Paint - Red                   4            24       3
492         Paint - Black                 4            14       4
494         Paint - Silver                4            12       5
 (10 row(s) affected)

B.对结果集中的所有行排名

下面的示例返回按薪金排名的前十名员工。 因为未指定 PARTITION BY 子句，所以，RANK 函数应用于结果集中的所有行。

USE AdventureWorks2012
SELECT TOP(10) BusinessEntityID, Rate,
RANK() OVER (ORDER BY Rate DESC) AS RankBySalary
FROM HumanResources.EmployeePayHistory AS eph1
WHERE RateChangeDate = (SELECT MAX(RateChangeDate)
                        FROM HumanResources.EmployeePayHistory AS eph2
                        WHERE eph1.BusinessEntityID = eph2.BusinessEntityID)
ORDER BY BusinessEntityID;

下面是结果集：

BusinessEntityID Rate                  RankBySalary
---------------- --------------------- --------------------
1                125.50                1
2                63.4615               4
3                43.2692               8
4                29.8462               19
5                32.6923               16
6                32.6923               16
7                50.4808               6
8                40.8654               10
9                40.8654               10
10               42.4808               9