Question

我是SQL Server和触发器的新手。我有一个现有的触发器，我需要自定义。有两个表产品（包含库存中的产品总数。数量）和OrdersLines（包含有关订单的所有信息。示例行将包含OrderID，ProductID和Amount）当我下订单时，产品金额是保留的。我需要触发器来检查新的订购金额是否超过数量。如果是，抛出RAISERROR，如果没有，让事务继续。

我无法识别要检查库存数量的总订单数量。

触发器适用于OrdersLines表我正在考虑做一些事情：

IF EXISTS ((SELECT *
            FROM Products AS p
            JOIN inserted AS i
            ON p.ProductID = i.ProductID
            JOIN OrdersLines AS o
            ON p.ProductID = o.ProductID
            WHERE (SUM(o.Amount) + i.Amount) <= p.Quantity)
BEGIN 
    GOTO ContinueTransaction
END ELSE BEGIN
    GOTO RollbackTransaction
    END

但我认为这不正确。同样在ELSE我需要RAISERROR来通知订单没有添加，但我不确定如何。有些论据可以放在那里，现在让我感到困惑。

Answer 1

create trigger CheckOrderAmount 
On orderLines 
for insert, update
As 
Begin
Set NoCount On;

   if exists (Select * from inserted I
                 join products p
                    on p.ProductID = i.ProductID
              group by i.ProductID 
              having SUM(i.Amount) > p.Quantity)
    begin
      rollback transaction
      raiserror("There are not enough items in inventory", 16, 1)
    end
end

Answer 2

以下问题解决了。对于插入触发器：

IF EXISTS (SELECT * 
            FROM atbv_Sales_Products p 
            JOIN inserted i
            ON p.ProductID = i.ProductID
            JOIN atbv_Sales_OrdersLines ol
            ON p.ProductID = i.ProductID
            GROUP BY i.ProductID, i.Amount, p.Quantity
            HAVING (SUM(ol.Amount) + i.Amount) > p.Quantity)
BEGIN
    DECLARE @ProductName NVARCHAR(60)
            SET @ProductName = (SELECT p.ProductName 
                                    FROM atbv_Sales_Products p
                                    JOIN inserted i 
                                    ON i.ProductID = p.ProductID)
            RAISERROR ('----There is not enough items (%s) left----', 18, 1, @ProductName) ROLLBACK TRANSACTION 
            RETURN
END

更新触发器：

IF EXISTS (SELECT * 
            FROM atbv_Sales_Products p 
            JOIN atbv_Sales_OrdersLines ol
            ON ol.ProductID = p.ProductID
            GROUP BY p.ProductID, ol.Amount, p.Quantity
            HAVING SUM(ol.Amount) > p.Quantity)
BEGIN
    DECLARE @ProductName NVARCHAR(60)
            SET @ProductName = (SELECT p.ProductName 
                                    FROM atbv_Sales_Products p
                                    JOIN atbv_Sales_OrdersLines ol
                                    ON ol.ProductID = p.ProductID
                                    GROUP BY p.ProductID, ol.Amount, p.Quantity, p.ProductName
                                    HAVING SUM(ol.Amount) > p.Quantity)
            RAISERROR ('----There is not enough items (%s) left----', 18, 1, @ProductName) ROLLBACK TRANSACTION 
            RETURN
END

在sql server中插入/更新触发器以检查值

2 个答案: