屬性A基於屬性B（Microsoft SQL Server 2014）

Question

例如，我有兩個表名爲Manager_Order和Book_Inventory。

Manager_Order(
    ID (PK), 
    Book_Name, 
    Quantity (Attribute A) 
) 

Book_Inventory(
    ID (PK), 
    Book_Name (FK on Manager_Order), 
    Quantity (Attribute B) 
) 

每次經理作出命令，我想自動的數量在Book_Inventory更新。

Answer 1

查找到更新觸發後使用。

下面是一個例子（未測試）：

CREATE TRIGGER [dbo].Update_Book_Inventory 
ON [dbo].Manager_Order 
FOR UPDATE 
AS 
BEGIN 
    SET NOCOUNT ON; 
     UPDATE [dbo].Book_Inventory 
     SET Quantity = i.Quantity 
      FROM [dbo].Book_Inventory 
      INNER JOIN INSERTED i ON [dbo].Book_Inventory.Book_Name = i.Book_Name 
END 

參考： https://www.mssqltips.com/sqlservertip/4024/sql-server-trigger-after-update-for-a-specific-value/

Answer 2

你可能會創建一個觸發器。

https://msdn.microsoft.com/en-us/library/ms189799(v=sql.110).aspx