Question

这个查询的狄更斯出了什么问题？

SELECT id,
       SUM(CASE myDate
             WHEN DATEDIFF(day, myDate, GETDATE()) = 0 THEN [Items]
             ELSE 0
           END)
FROM   myTable
GROUP  BY id

???

错误说

"Incorrect syntax near '='.

Answer 1

SUM(CASE myDate WHEN DATEDIFF(day, myDate, GETDATE()) )你错过了一个封闭的支架我想

Answer 2

这是您想要的查询：

SELECT id,
       SUM(CASE WHEN DATEDIFF(day, myDate, GETDATE()) = 0 THEN [Items] ELSE 0 END)
FROM myTable
GROUP BY id;

myDate之后的case没有为您做任何事情。语法上允许case语句的替代形式：

sum(case mydate when '2013-01-01' then 'New Years Day' . . .

但是当你在when之后有一个表达时。

Answer 3

mydate

之后您不需要CASE

SELECT  id, 
        SUM(CASE 
            WHEN DATEDIFF(day, myDate, GETDATE()) = 0 
            THEN [Items] ELSE 0 END) 

FROM myTable GROUP BY id;

Answer 4

SELECT id， SUM（CASE myDate 当DATEDIFF（day，myDate，GETDATE（）= 0）那么[Items] ELSE 0 结束）来自myTable GROUP BY id

这是正确的

选择不会工作

4 个答案: