来自 Microsoft SQL Server 2012 T-SQL 基础的示例查询不起作用

Question

我最近开始关注 Microsoft SQL Server 2012 T-SQL Fundamental book 来学习 T-SQL。我尝试在 SQL Server 2008 r2 中执行以下查询

SELECT empid, ordermonth, val,
SUM(val) OVER(PARTITION BY empid
              ORDER BY ordermonth
              ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS runval
FROM Sales.EmpOrders;

查询无法执行并显示以下错误消息

Msg 102, Level 15, State 1, Line 5
Incorrect syntax near 'ROWS'.

这是 sales.emporders 视图的片段

empid   ordermonth                  qty     val         numorders
-----------------------------------------------------------------
5       2007-10-01 00:00:00.000     361     7581.33         9
6       2007-06-01 00:00:00.000     173     3464.81         7
9       2007-09-01 00:00:00.000     93      8776.15         5
5       2008-02-01 00:00:00.000     276     5377.06         15
5       2007-07-01 00:00:00.000     213     6475.40         5
4       2006-10-01 00:00:00.000     613     13718.97        27

在想办法解决 sql server 2008 r2 时需要帮助

Answer 1

这不是 SQL Server 2012 的功能。您可以使用 OVER 函数，但在 2008R2 中没有以下功能：ROWS BETWEEN UNBOUNDED PRECEDING

见：

https://msdn.microsoft.com/en-us/library/ms189461(v=sql.105).aspx (2008R2)

与

https://msdn.microsoft.com/en-us/library/ms189461(v=sql.110).aspx (2012)

Answer 2

SELECT empid, 
       ordermonth, 
       val,
       (SELECT SUM(val) 
        FROM Sales.EmpOrders ee 
        WHERE e.empid=ee.empid 
        AND ee.ordermonth<=e.ordermonth) AS runval
FROM Sales.EmpOrders e;

Answer 3

如果您使用的是 UNBOUNDED PRECEDING，我认为您可以放弃它
你试过了吗？

SELECT empid, ordermonth, val
     , SUM(val) OVER(PARTITION BY empid ORDER BY ordermonth) AS runval
FROM Sales.EmpOrders;