我编写了以下存储过程:
ALTER PROCEDURE [dbo].[sp_Accounts_ValidateLogin]
@EmailAddress varchar(255),
@Password varchar(20)
AS
DECLARE @UserID int
SELECT @UserID = UserID
FROM Accounts_Users
WHERE EmailAddress = @EmailAddress and Password = @Password
IF @UserID != NULL
RETURN @UserID
ELSE
RETURN -1
执行此过程时,它显示,
No rows affected.
(0 row(s) returned)
@RETURN_VALUE = -1
但是每当我将SELECT
声明重写为,
SELECT UserID
FROM Accounts_Users
WHERE EmailAddress = @EmailAddress and Password = @Password
结果是:
UserID
---------------------------------------------------------------------------------------
3
No rows affected.
(1 row(s) returned)
@RETURN_VALUE = -1
@UserID
我的问题是为什么变量没有在第一个选择语句中设置?