ROW_NUMBER、RANK、DENSE_RANK的用法
(愛新覺羅.毓華? 2007-12-16? 廣東深圳)

SQL Server 2005 引入幾個新的排序(排名)函數,如ROW_NUMBER、RANK、DENSE_RANK等。
這些新函數使您可以有效地分析數據以及向查詢的結果行提供排序值。

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ROW_NUMBER()

說明：返回結果集分區內行的序列號，每個分區的第一行從 1 開始。
語法：ROW_NUMBER () OVER ( [ ] ) 。
備注：ORDER BY 子句可確定在特定分區中為行分配唯一 ROW_NUMBER 的順序。
參數： ：將 FROM 子句生成的結果集劃入應用了 ROW_NUMBER 函數的分區。
????? ：確定將 ROW_NUMBER 值分配給分區中的行的順序。
返回類型：bigint 。

示例：
/*以下示例將根據年初至今的銷售額，返回 AdventureWorks 中銷售人員的 ROW_NUMBER。*/

USE AdventureWorks
GO
SELECT c.FirstName, c.LastName, ROW_NUMBER() OVER(ORDER BY SalesYTD DESC) AS 'Row Number', s.SalesYTD, a.PostalCode
FROM Sales.SalesPerson s JOIN Person.Contact c on s.SalesPersonID = c.ContactID
JOIN Person.Address a ON a.AddressID = c.ContactID
WHERE TerritoryID IS NOT NULL AND SalesYTD <> 0
/*
FirstName? LastName??? Row Number? SalesYTD????? PostalCode
---------? ----------? ----------? ------------? ----------------------------
Shelley??? Dyck??????? 1?????????? 5200475.2313? 98027
Gail?????? Erickson??? 2?????????? 5015682.3752? 98055
Maciej???? Dusza?????? 3?????????? 4557045.0459? 98027
Linda????? Ecoffey???? 4?????????? 3857163.6332? 98027
Mark?????? Erickson??? 5?????????? 3827950.238?? 98055
Terry????? Eminhizer?? 6?????????? 3587378.4257? 98055
Michael??? Emanuel???? 7?????????? 3189356.2465? 98055
Jauna????? Elson?????? 8?????????? 3018725.4858? 98055
Carol????? Elliott???? 9?????????? 2811012.7151? 98027
Janeth???? Esteves???? 10????????? 2241204.0424? 98055
Martha???? Espinoza??? 11????????? 1931620.1835? 98055
Carla????? Eldridge??? 12????????? 1764938.9859? 98027
Twanna???? Evans?????? 13????????? 1758385.926?? 98055
(13 行受影響)
*/

/*以下示例將返回行號為 50 到 60（含）的行，并以 OrderDate 排序。*/
USE AdventureWorks;
GO
WITH OrderedOrders AS
(SELECT SalesOrderID, OrderDate,
ROW_NUMBER() OVER (order by OrderDate)as RowNumber
FROM Sales.SalesOrderHeader )
SELECT *
FROM OrderedOrders
WHERE RowNumber between 50 and 60;
/*
SalesOrderID OrderDate?????????????? RowNumber
------------ ----------------------- --------------------
43708??????? 2001-07-03 00:00:00.000 50
43709??????? 2001-07-03 00:00:00.000 51
43710??????? 2001-07-03 00:00:00.000 52
43711??????? 2001-07-04 00:00:00.000 53
43712??????? 2001-07-04 00:00:00.000 54
43713??????? 2001-07-05 00:00:00.000 55
43714??????? 2001-07-05 00:00:00.000 56
43715??????? 2001-07-05 00:00:00.000 57
43716??????? 2001-07-05 00:00:00.000 58
43717??????? 2001-07-05 00:00:00.000 59
43718??????? 2001-07-06 00:00:00.000 60
(11 行受影響)
*/

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RANK()

說明：返回結果集的分區內每行的排名。行的排名是相關行之前的排名數加一。
語法：RANK () OVER ( [ < partition_by_clause > ] < order_by_clause > )
備注：如果兩個或多個行與一個排名關聯，則每個關聯行將得到相同的排名。
????? 例如，如果兩位頂尖銷售員具有同樣的 SalesYTD 值，他們將并列第一。
????? 由于已有兩行排名在前，所以具有下一個最大 SalesYTD 的銷售人員將排名第三。
????? 因此，RANK 函數并不總返回連續整數。
????? 用于整個查詢的排序順序決定了行在結果集中的顯示順序。這也隱含了行在每個分區中的排名。
參數：< partition_by_clause > ：將 FROM 子句生成的結果集劃分為要應用 RANK 函數的分區。
????? < order_by_clause >：確定將 RANK 值應用于分區中的行時所基于的順序。
返回類型：bigint

示例：
/*以下示例按照數量對清單中的產品進行了排名。行集按 LocationID 分區，按 Quantity 排序。
USE AdventureWorks;
GO
SELECT i.ProductID, p.Name, i.LocationID, i.Quantity, RANK() OVER (PARTITION BY i.LocationID order by i.Quantity) as RANK
FROM Production.ProductInventory i JOIN Production.Product p
ON i.ProductID = p.ProductID
ORDER BY p.Name
GO
/*
ProductID?? Name?????????????????????????????????????????????? LocationID Quantity RANK
----------- -------------------------------------------------- ---------- -------- --------------------
1?????????? Adjustable Race??????????????????????????????????? 6????????? 324????? 71
1?????????? Adjustable Race??????????????????????????????????? 1????????? 408????? 78
1?????????? Adjustable Race??????????????????????????????????? 50???????? 353????? 117
2?????????? Bearing Ball?????????????????????????????????????? 6????????? 318????? 67
2?????????? Bearing Ball?????????????????????????????????????? 1????????? 427????? 85
2?????????? Bearing Ball?????????????????????????????????????? 50???????? 364????? 122
3?????????? BB Ball Bearing??????????????????????????????????? 50???????? 324????? 106
3?????????? BB Ball Bearing??????????????????????????????????? 1????????? 585????? 110
3?????????? BB Ball Bearing??????????????????????????????????? 6????????? 443????? 115
4?????????? Headset Ball Bearings????????????????????????????? 1????????? 512????? 99
4?????????? Headset Ball Bearings????????????????????????????? 6????????? 422????? 108
4?????????? Headset Ball Bearings????????????????????????????? 50???????? 388????? 140
316???????? Blade????????????????????????????????????????????? 10???????? 388????? 33
......
(1069 行受影響)
*/

ROW_NUMBER、RANK、DENSE_RANK的用法