T-SQL中是否有一个异或运算符？

Question

这是我的发言

IF (@UserName IS NULL AND @EditorKey IS NULL) OR (@UserName IS NOT NULL AND @EditorKey IS NOT NULL) BEGIN
    RAISERROR ('One of @UserName, @EditorKey must be non-null.', 15, 0)
    RETURN
END

我想要的是能够做这样的事情:

IF (@UserName IS NOT NULL) XOR (@EditorKey IS NOT NULL) BEGIN
    RAISERROR ('One of @UserName, @EditorKey must be non-null.', 15, 0)
    RETURN
END

对于两个参数来说,这并不是什么大不了的事,但是有些过程有三个或四个只有一个可以传递,其余的应该为空.

Answer 1

不是很简洁,但你可以像这样扩展逻辑:

WHERE
    (NOT ((@UserName IS NOT NULL) AND (@EditorKey IS NOT NULL))) AND
    ((@UserName IS NOT NULL) OR (@EditorKey IS NOT NULL))

或者使用按位XOR运算符(^):

WHERE
    (CASE WHEN (@UserName IS NOT NULL) THEN 1 ELSE 0 END) ^
    (CASE WHEN (@EditorKey IS NOT NULL) THEN 1 ELSE 0 END) = 1

您可以使用类似的方法,其中有三个或四个参数,并且只有一个必须具有值:

WHERE
    (CASE WHEN (@Var1 IS NOT NULL) THEN 1 ELSE 0 END) +
    (CASE WHEN (@Var2 IS NOT NULL) THEN 1 ELSE 0 END) +
    (CASE WHEN (@Var3 IS NOT NULL) THEN 1 ELSE 0 END) +
    (CASE WHEN (@Var4 IS NOT NULL) THEN 1 ELSE 0 END) = 1