SQL查询中的多个案例 [英] Multiple Cases in SQL query

问题描述

下面给出了一个SQL查询，该查询通过根据Card ar选择最大和最小日期来执行DateDIff操作，你可以说id，

这里'查询

There is a SQL query given below, that query performs DateDIff operation by slecting max and min date according to Card ar you can say id,
here' the query

SELECT
--COUNT(DIFF)
Count(DATEDIFF(D, MinDate, MaxDate)/30) AS DIFF

FROM (
SELECT

   MAX(TDate) AS MaxDate,
   MIN(TDate) AS MinDate
   FROM EDATA
   GROUP BY TCard
)a
Group by DATEDIFF(D, MinDate, MaxDate)/30

现在我想在此查询中应用某种排序之前执行DateDiff操作（排序可以基于几个参数，如年龄，名称等，但根据案例一次1）

现在我想知道如何通过此查询应用案例的地方？

Now i want to apply some kind of sorting in this query before performing DateDiff operation (sorting can be based on several parameters like age, name etc. but 1 at a time according to the cases)
Now I want to know How to apply cases over this query an where?

推荐答案

您好，



试试这个...

< br $> b $ b

Hi,

Try this...

ORDER BY
CASE
   WHEN cond.1 = 0 THEN 5
   WHEN cond.1 <> 0 THEN 4
   ELSE 1 END desc,
CASE
   WHEN cond.2 = 0 THEN 5
   WHEN cond.2 <> 0 THEN 4
   ELSE 9 END desc,
col1 ASC, col2 ASC, col3 ASC

希望这会对你有所帮助。



干杯

Hope this will help you.

Cheers

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