SQL Server存储过程为total添加两个声明的值
到目前为止,我在存储过程中使用了两个声明的变量:SQL Server存储过程为total添加两个声明的值,sql,sql-server-2008,stored-procedures,sum,Sql,Sql Server 2008,Stored Procedures,Sum,到目前为止,我在存储过程中使用了两个声明的变量: SET @QuestionPoints = (SELECT SUM(points) FROM tb_responses WHERE userid = @UserId AND id = @ID) SET @EventPoints =(SELECT SUM(dbo.tb_events.p
SET @QuestionPoints = (SELECT SUM(points)
FROM tb_responses
WHERE userid = @UserId
AND id = @ID)
SET @EventPoints =(SELECT SUM(dbo.tb_events.points)
FROM dbo.tb_attendance
INNER JOIN dbo.tb_events
ON dbo.tb_attendance.eventid = dbo.tb_events.dbid
WHERE dbo.tb_attendance.userid = @UserID
AND dbo.tb_attendance.didattend = 'Y'
AND dbo.tb_events.id = @ID)
如何将@QuestionPoints和@EventPoints相加以获得总分?我可以使用“+”添加它们并将其分配给第三个声明的变量,还是使用一个全局语句
谢谢
James如果您不再需要这两个组件变量,您可以(重新)使用其中一个变量:
SET @QuestionPoints = ...
SET @EventPoints = ...
SET @QuestionPoints = @QuestionPoints + @EventPoints
但是在添加SUM()
时要小心,因为它们可以为NULL<代码>20+null=>null。如有必要,请使用ISNULL,例如
SET @QuestionPoints = isnull(@QuestionPoints, 0) + isnull(@EventPoints, 0)
如果您仍然需要它们,那么您可以申报第三个
DECLARE @TotalPoints float --- or numeric or whatever the type should be
SET @TotalPoints = @QuestionPoints + @EventPoints
您甚至可以跳过单个变量
SET @QuestionPoints = (SELECT SUM(POINTS) FROM tb_Responses WHERE UserID = @UserId AND ID = @ID)
+
(SELECT SUM(dbo.tb_Events.Points) FROM dbo.tb_Attendance INNER JOIN dbo.tb_Events ON dbo.tb_Attendance.EventID = dbo.tb_Events.dbID WHERE dbo.tb_Attendance.UserID = @UserID AND dbo.tb_Attendance.DidAttend = 'Y' AND dbo.tb_Events.ID = @ID)
如果您需要@QuestionPoints和@EventPoints保留其当前值,那么是的,您需要第三个变量:
DECLARE @totalPoints INT
SET @totalPoints = @QuestionPoints + @EventPoints
如果不需要它们保留相同的值,则只需覆盖其中一个:
SET@QuestionPoints=@QuestionPoints+@EventPoints
或者,在SQL的最新版本中:
SET@QuestionPoints+=@EventPoints
您可以在一条语句中完成此操作
Set @Total = (
Select Sum( Z.points )
From (
Select points
From tb_responses
Where userid = @UserId
And Id = @Id
Union All
Select E.points
From dbo.tb_attendance As A
Join dbo.tb_events As E
On E.dbid = A.eventid
Where A.userid = @UserId
And A.didattend = 'Y'
And E.Id = @ID
) As Z
)
非常感谢。只是想知道,还可以使用另一个变量(@TotalPoints)并将前两个变量相加?@James是的,这是可能的,正如@Richard已经在他的一个示例(@TotalPoints)中所示。每个回答我问题的人都回答了我的问题,但包括有关处理空值的信息非常有用。我将不得不处理这一点,因为参与者可能会从回答的问题中获得分数,但不会从出席活动中获得分数(反之亦然)。更合适的标题是“两个声明变量”,而不是值。感谢所有反应如此迅速的人。