Question

我想在插入多个值时触发触发器，即使它们像这样重复：

假设值为0（表1）：

插入上面的值（在创建触发器时）应该给我们：

但它的工作正常，如果买的价值是99，那么＆＃34; Prod1＆＃34;例如，我跑：

关于Prod2，由于Prod1有一个约束错误，它根本没有更新，因为它有一个约束错误。

Answer 1

您可以使用IIF或CASE来限制所需的限额：

UPDATE T1
SET Bought = IIF((Bought + uc.UpdCount) < 100, Bought + uc.UpdCount, 100)
FROM TABLE_1 T1
JOIN (
    SELECT ProdName, COUNT(*) as UpdCount 
    FROM Inserted 
    GROUP BY ProdName
) uc ON uc.Name = T1.ProdName
WHERE T1.Bought < 100;

使用MERGE语句进行upsert，它看起来像这样：

MERGE TABLE_1 AS t  
USING (
    SELECT ProdName, COUNT(*) as UpdCount 
    FROM Inserted 
    GROUP BY ProdName
) AS s (Name, UpdCount) ON (t.ProdName = s.Name)  
WHEN MATCHED THEN   
  UPDATE SET Bought = IIF((t.Bought + s.UpdCount) < 100, t.Bought + s.UpdCount, 100)
WHEN NOT MATCHED THEN  
  INSERT (ProdName, Bought) VALUES (s.Name, IIF(s.UpdCount < 100, s.UpdCount, 100));

执行触发器？

1 个答案: