ROW_NUMBER()
说明：返回结果集分区内行的序列号，每个分区的第一行从 1 开始。
语法：ROW_NUMBER () OVER ( [ <partition_by_clause> ] <order_by_clause> ) 。
备注：ORDER BY 子句可确定在特定分区中为行分配唯一 ROW_NUMBER 的顺序。
参数：<partition_by_clause> ：将 FROM 子句生成的结果集划入应用了 ROW_NUMBER 函数的分区。
<order_by_clause>：确定将 ROW_NUMBER 值分配给分区中的行的顺序。
返回类型：bigint 。
示例：
/*以下示例将根据年初至今的销售额，返回 AdventureWorks 中销售人员的 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 行受影响)
*/
/*以下示例将返回行号为 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 行受影响)
*/
