我有一些代码,其中WHERE子句中使用的变量可以为空.因此,我必须使用IF ELSE查询数据以检查NULL.无论如何在一个查询中写入？
- DECLARE @OrderID UNIQUEIDENTIFIER
- IF @OrderID IS NULL
- BEGIN
- SELECT *
- FROM Customers
- WHERE OrderID IS NULL
- END
- ELSE
- BEGIN
- SELECT *
- FROM Customers
- WHERE OrderID = @OrderID
- END
解决方法@H_301_6@
- SELECT *
- FROM Customers
- WHERE EXISTS (SELECT OrderID INTERSECT SELECT @OrderID)
会有效地做到这一点.
- SELECT *
- FROM Customers
- WHERE EXISTS (SELECT OrderID INTERSECT SELECT @OrderID)
会有效地做到这一点.
