问题
Is it posible to use case in where in clause? Something like this:
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)
This code gives the error : Incorrect syntax near ','.
回答1:
No you can't use case and in like this. But you can do
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 you can reduce that to
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)
since or P.Status IN (1,3) gives you also all records of @Status='published' and P.Status IN (1,3)
回答2:
I realize this has been answered, but there is a slight issue with the accepted solution. It will return false positives. Easy to fix:
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
Parentheses aren't needed (although perhaps easier to read hence why I included them).
回答3:
I believe you can use a case statement in a where clause, here is how I do it:
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
)
This method has worked for me time and again. try it!
回答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
回答5:
maybe you can try this way
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'
In this way if @Status = 'published', the query will check if P.Status is among 1 or 3, it will return TRUE else 'FALSE'. This will be matched with TRUE at the end
Hope it helps.
回答6:
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
来源：https://stackoverflow.com/questions/19271853/sql-use-case-statement-in-where-in-clause