SQL Server 2005のトリガが動作しない

Question

order_detailsというテーブルとbook_inventoryというテーブルがあります。

order_detailsで私がquantity_orderedになったとき、その値をquantity_in_stockからbook_inventoryに減らす必要があります。ここで

が私のコードです：？

create TRIGGER [dbo].[book] 
    ON [dbo].[order_details] 
    AFTER UPDATE 
AS 

IF UPDATE(quantity_ordered) 
    UPDATE book_inventory 
    SET book_inventory.quantity_in_stock = book_inventory.quantity_in_stock - order_details.quantity_ordered 
    FROM order_details 
    WHERE book_inventory.isbn = order_details.isbn 

Answer 1

[OK]を、このクエリを記述する適切な方法は

create TRIGGER [dbo].[book] 
    ON [dbo].[order_details] 
    AFTER UPDATE 
AS 

IF UPDATE(quantity_ordered) 
    UPDATE book_inventory 
    SET book_inventory.quantity_in_stock = book_inventory.quantity_in_stock - i.quantity_ordered + d.quantity_ordered 
    FROM INSERTED i 
    JOIN DELETED d 
     ON d.isbn = i.isbn 
    WHERE book_inventory.isbn = i.isbn