Question

是否可以在子句子句中使用 case ？像这样：

DECLARE @Status VARCHAR(50); SET @Status='published'; SELECT * FROM Product P WHERE P.Status IN (CASE WHEN @Status='published' THEN (1,3) WHEN @Status='standby' THEN (2,5,9,6) WHEN @Status='deleted' THEN (4,5,8,10) ELSE (1,3) END)

此代码提供错误：'，'附近的语法不正确。

Answer 1

不，你不能像这样使用case和in。但你可以做到

SELECT * FROM Product P    
WHERE @Status='published' and P.Status IN (1,3)
or @Status='standby' and P.Status IN  (2,5,9,6)
or @Status='deleted' and P.Status IN (4,5,8,10)
or P.Status IN (1,3)

BTW你可以减少到

SELECT * FROM Product P    
WHERE @Status='standby' and P.Status IN (2,5,9,6)
or @Status='deleted' and P.Status IN (4,5,8,10)
or P.Status IN (1,3)

因为or P.Status IN (1,3)还会为您提供@Status='published' and P.Status IN (1,3)

的所有记录

Answer 2

我意识到这已得到解答，但是已接受的解决方案存在轻微问题。它会返回误报。易于修复：

SELECT * FROM Products P    
WHERE (@Status='published' and P.Status IN (1,3))
   or (@Status='standby' and P.Status IN  (2,5,9,6))
   or (@Status='deleted' and P.Status IN (4,5,8,10))
   or (@Status not in ('published','standby','deleted') and P.Status IN (1,2))

SQL Fiddle Demo

不需要括号（尽管可能更容易阅读，因此我将它们包括在内）。

Answer 3

我相信你可以在where子句中使用case语句，这是我的工作方式：

Select 
ProductID
OrderNo,
OrderType,
OrderLineNo
From Order_Detail
Where ProductID in (
Select Case when (@Varibale1 != '') 
then (Select ProductID from Product P Where .......)
Else (Select ProductID from Product)
End as ProductID
)

这种方法一次又一次对我有用。试试吧！

Answer 4

 select  * from Tran_LibraryBooksTrans LBT  left join
 Tran_LibraryIssuedBooks LIB ON   case WHEN LBT.IssuedTo='SN' AND
 LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN 1 when LBT.IssuedTo='SM'
 AND LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN 1 WHEN
 LBT.IssuedTo='BO' AND LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN 1
 ELSE 0 END`enter code here`select  * from Tran_LibraryBooksTrans LBT 
 left join Tran_LibraryIssuedBooks LIB ON   case WHEN LBT.IssuedTo='SN'
 AND LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN 1 when
 LBT.IssuedTo='SM' AND LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN 1
 WHEN LBT.IssuedTo='BO' AND LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN
 1 ELSE 0 END

Answer 5

 SELECT  * FROM Tran_LibraryBooksTrans LBT  
 LEFT JOIN Tran_LibraryIssuedBooks LIB ON 
 CASE WHEN LBT.IssuedTo='SN' AND LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN 1
      WHEN LBT.IssuedTo='SM' AND LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN 1 
      WHEN LBT.IssuedTo='BO' AND LBT.LIBRARYTRANSID=LIB.LIBRARYTRANSID THEN 1
 ELSE 0 END

Answer 6

也许你可以尝试这种方式

SELECT * FROM Product P WHERE (CASE WHEN @Status = 'published' THEN (CASE WHEN P.Status IN (1, 3) THEN 'TRUE' ELSE FALSE END) WHEN @Status = 'standby' THEN (CASE WHEN P.Status IN (2, 5, 9, 6) THEN 'TRUE' ELSE 'FALSE' END) WHEN @Status = 'deleted' THEN (CASE WHEN P.Status IN (4, 5, 8, 10) THEN 'TRUE' ELSE 'FALSE' END) ELSE (CASE WHEN P.Status IN (1, 3) THEN 'TRUE' ELSE 'FALSE' END) END) = 'TRUE'

这样，如果@Status ='published'，查询将检查P.Status是否在1或3之间，它将返回TRUE，否则为'FALSE'。这将在最后与TRUE匹配

希望它有所帮助。

Answer 7

根据我的方案，我做到了“在WHERE IN子句中使用CASE语句”，如下所示：

@AdjType varchar(20) = 'Value', 
@Base varchar(20) = 'Common'
where 
(select CASE WHEN SA.IsPersentage = 0 THEN 'Value' 
       WHEN SA.IsPersentage = 1 THEN 'Presentage' END) Like @AdjType
and (Select CASE WHEN SA.IsDependOnBasicSalary = 0 THEN 'Common' 
        WHEN SA.IsDependOnBasicSalary = 1 THEN 'Basic Salary' END) like @Base

SQL在WHERE IN子句中使用CASE语句

7 个答案: