运行总共使用了 over 子句

Question

我是运行 SQL Server 2008，我目前正在尝试更多地了解 over 子句，我以前用过它，但只是用 row_number() 并且我学会了您可以将聚合函数与它一起使用，并创建诸如运行总数之类的东西。

我创建了以下测试数据库。

CREATE TABLE sales
(
    employee nvarchar(50),
    sales decimal(18, 2),
    datesale datetime
);

Insert into sales Values('John','54.23','2017-01-30 08:00:00.000')
Insert into sales Values('John','123.96','2017-01-30 09:00:00.000')
Insert into sales Values('John','534.20','2017-01-30 10:00:00.000')
Insert into sales Values('Ben','98.34','2017-01-29 04:00:00.000')
Insert into sales Values('Ben','126.32','2017-01-29 05:00:00.000')

并使用以下查询为每位员工创建运行总和

select 
    employee, sales, datesale, 
    SUM(sales) over (partition by employee order by datesale) as mvgsum 
from sales

在 SQL Fiddle 使用 SQL Server 2008 我得到以下结果

 | employee |  sales |                  datesale | mvgsum |
 |----------|--------|---------------------------|--------|
 |      Ben |  98.34 | January, 29 2017 04:00:00 |  98.34 |
 |      Ben | 126.32 | January, 29 2017 05:00:00 | 224.66 |
 |     John |  54.23 | January, 30 2017 08:00:00 |  54.23 |
 |     John | 123.96 | January, 30 2017 09:00:00 | 178.19 |
 |     John |  534.2 | January, 30 2017 10:00:00 | 712.39 |

但是，在 SQL Server Management Studio 中，在 SQL Server 2008 数据库上，我使用相同的查询、相同的 table 结构和数据得到以下错误。

Incorrect syntax near 'order'.

可能是什么原因造成的？

Answer 1

SUM() OVER() 在 SQL Server 2008 中不受支持。

您可以使用相关子查询：

select employee,
    sales,
    datesale,
    (
        select sum(sales)
        from sales s2
        where s1.employee = s2.employee
            and s2.datesale <= s1.datesale
        ) mvgsum
from sales s1

或CROSS APPLY:

select employee,
    sales,
    datesale,
    x.mvgsum
from sales s1
cross apply (
    select sum(sales) mvgsum
    from sales s2
    where s1.employee = s2.employee
        and s2.datesale <= s1.datesale
    ) x

运行总共使用了 over 子句

Running total using over clause

sql

sql-server

sql-server-2008

window-functions

运行 总共使用了 over 子句

Running total using over clause

sql

sql-server

sql-server-2008

window-functions

运行总共使用了 over 子句