ORDER BY 子句的 CASE WHEN 语句 [英] CASE WHEN statement for ORDER BY clause
问题描述
我使用的是 SQL Server 2008 R2.
I am using SQL Server 2008 R2.
我想要对表中的记录进行基于优先级的排序.
I want the priority based sorting for records in a table.
所以我在 ORDER BY 子句中使用 CASE WHEN 语句.ORDER BY 子句如下:
So that I am using CASE WHEN statement in ORDER BY clause. The ORDER BY clause is as below :
ORDER BY
CASE WHEN TblList.PinRequestCount <> 0 THEN TblList.PinRequestCount desc, TblList.LastName ASC, TblList.FirstName ASC, TblList.MiddleName ASC END,
CASE WHEN TblList.HighCallAlertCount <> 0 THEN TblList.HighCallAlertCount desc, TblList.LastName ASC, TblList.FirstName ASC, TblList.MiddleName ASC END,
Case WHEN TblList.HighAlertCount <> 0 THEN TblList.HighAlertCount DESC, TblList.LastName ASC, TblList.FirstName ASC, TblList.MiddleName ASC END,
CASE WHEN TblList.MediumCallAlertCount <> 0 THEN TblList.MediumCallAlertCount DESC, TblList.LastName ASC, TblList.FirstName ASC, TblList.MiddleName ASC END,
Case WHEN TblList.MediumAlertCount <> 0 THEN TblList.MediumAlertCount DESC, TblList.LastName ASC, TblList.FirstName ASC, Patlist.MiddleName ASC END
但它给出了关键字'desc'附近的语法不正确
有什么解决办法吗?
我也可以:
TblList.PinRequestCount <> 0 and TblList.HighCallAlertCount <> 0 and
TblList.HighAlertCount <> 0` and TblList.MediumCallAlertCount <> 0 and
TblList.MediumAlertCount <> 0
同时.
推荐答案
CASE
是一个表达式 - 它返回一个单个标量值(每行).它不能返回其他事物的解析树的复杂部分,例如 SELECT
语句的 ORDER BY
子句.
CASE
is an expression - it returns a single scalar value (per row). It can't return a complex part of the parse tree of something else, like an ORDER BY
clause of a SELECT
statement.
看起来你只需要:
ORDER BY
CASE WHEN TblList.PinRequestCount <> 0 THEN TblList.PinRequestCount END desc,
CASE WHEN TblList.HighCallAlertCount <> 0 THEN TblList.HighCallAlertCount END desc,
Case WHEN TblList.HighAlertCount <> 0 THEN TblList.HighAlertCount END DESC,
CASE WHEN TblList.MediumCallAlertCount <> 0 THEN TblList.MediumCallAlertCount END DESC,
Case WHEN TblList.MediumAlertCount <> 0 THEN TblList.MediumAlertCount END DESC,
TblList.LastName ASC, TblList.FirstName ASC, TblList.MiddleName ASC
或者可能:
ORDER BY
CASE
WHEN TblList.PinRequestCount <> 0 THEN TblList.PinRequestCount
WHEN TblList.HighCallAlertCount <> 0 THEN TblList.HighCallAlertCount
WHEN TblList.HighAlertCount <> 0 THEN TblList.HighAlertCount
WHEN TblList.MediumCallAlertCount <> 0 THEN TblList.MediumCallAlertCount
WHEN TblList.MediumAlertCount <> 0 THEN TblList.MediumAlertCount
END desc,
TblList.LastName ASC, TblList.FirstName ASC, TblList.MiddleName ASC
判断上述哪个(或其他)是您要查找的内容有点棘手,因为您已经:解释您要实现的实际排序顺序,并且 b) 没有提供任何示例数据和预期结果,我们可以尝试从中推导出您想要达到的实际排序顺序.
It's a little tricky to tell which of the above (or something else) is what you're looking for because you've a) not explained what actual sort order you're trying to achieve, and b) not supplied any sample data and expected results, from which we could attempt to deduce the actual sort order you're trying to achieve.
这可能就是我们正在寻找的答案:
This may be the answer we're looking for:
ORDER BY
CASE
WHEN TblList.PinRequestCount <> 0 THEN 5
WHEN TblList.HighCallAlertCount <> 0 THEN 4
WHEN TblList.HighAlertCount <> 0 THEN 3
WHEN TblList.MediumCallAlertCount <> 0 THEN 2
WHEN TblList.MediumAlertCount <> 0 THEN 1
END desc,
CASE
WHEN TblList.PinRequestCount <> 0 THEN TblList.PinRequestCount
WHEN TblList.HighCallAlertCount <> 0 THEN TblList.HighCallAlertCount
WHEN TblList.HighAlertCount <> 0 THEN TblList.HighAlertCount
WHEN TblList.MediumCallAlertCount <> 0 THEN TblList.MediumCallAlertCount
WHEN TblList.MediumAlertCount <> 0 THEN TblList.MediumAlertCount
END desc,
TblList.LastName ASC, TblList.FirstName ASC, TblList.MiddleName ASC
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