Question

每当我尝试对来自同一列的数据使用case语句时，我总是会遇到null值问题。数据库中的数据：

Month   Sum
Jan     1000
Feb     2000
Mar     3000

期望的结果：

Jan    Feb     Mar
1000   2000    3000

当我尝试使用case语句时，我遇到了null问题，并得到如下结果：

Jan      Feb      Mar
1000     Null     Null
Null     2000     Null
Null     Null     3000

以下是创建空值问题的代码。

select AccountID,
sum(Case when DATEPART(month,EndDateTime) = 10 then Budget End) period1,
sum(case when DATEPART(month,EndDateTime) = 11 then Budget end) period2,
sum(case  when DATEPART(month,EndDateTime) = 12 then Budget End) period3,
Description,
from Budget
where DATEPART(month,EndDateTime) in ('10','11','12')
group by AccountID,Description,EndDateTime
order by AccountID,Description,EndDateTime;

使用Pivot功能，我能够生成所需的结果。

SELECT
    AccountID,
    [1] AS Jan,
    [2] AS Feb,
    [3] AS Mar,
    [4] AS Apr,
    [5] AS May,
    [6] AS Jun,
    [7] AS Jul,
    [8] AS Aug,
    [9] AS Sep,
    [10] AS Oct,
    [11] AS Nov,
    [12] AS Dec
FROM
(Select 
AccountID,
Budget,
 MONTH(EndDateTime) as TMonth
  from
    dbo.Budget) source
PIVOT
(
    SUM(Budget)
    FOR TMonth
    IN ( [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12] )
) AS pvtMonth

我现在面临的当前问题是我需要再添加一个sum函数Sum（BudgetNet）。有什么建议？感谢。

Answer 1

对于您想要的结果类型，看起来您应该使用PIVOT而不是CASE。

案例陈述无效问题

1 个答案: