Question

我对Oracle的程序有疑问，希望你们帮助我。我有这3个表：

成分： Ingredient_Number PK Ingredient_Name， Quantity_On_Hand，订货点， Current_Cost，

MENU_ITEM
Menu_Item_Number PK Menu_Item_Name，目前的价格， Production_Cost，

Menu_Item_Ingredient
Menu_Item_Number PK / FK， Ingredient_Number PK / FK ， Quantity_Needed，

如果Production_Cost＆lt;

我尝试创建更新Menu_Item表上的Production_Cost的过程。 Quantity_Needed * Current_cost * 0.75我最终得到了这些代码：

Create or Replace Procedure PR_Check_Cost
(P_Menu_Item_Number Number, P_Ingredient Number)
authid current_user 
IS
V_Productiton_Cost Number (6,2);
V_Current_Cost
V_Quantity_Needed Number (5,2);

CURSOR C_Cost 
IS
Select Production_Cost
INTO V_Production_Cost
From Menu_Item
Where Menu_Item_Number= P_Menu_Item_Number; 


Begin
Open C_Cost;

Select Quantity_Needed
Into V_Quantity_Needed
FROM Menu_Item_Ingredient
WHERE Ingredient_Number = P_Ingredient_Number
AND Menu_Item_Number = P_Menu_Item_Number;

Select Current_Cost
INTO V_CurrentCost
From Ingredient
Where Ingredient_Number = P_Ingredient_Number;

Fetch C_Product_Cost INTO V_Current_Cost, V_Quantity_Needed
While C_Product_Cost%FOUND LOOP


If (V_Quantity_Needed * V_Current_Cost * 0.75) > V_Production_Cost
{
    UPDATE Menu_Item
    SET Production_Cost = V_Quantity_Needed * V_Current_Cost * 0.75
    Where Menu_Item_Number = P_Menu_Item_Number
    AND Ingredient-Number = P_Ingredient_Number; 
}


End PR_Check_Cost;/
SHOW ERRORS;

无论如何，只要用户更新Current_Cost和Quantity_Needed列而不输入 Menu_Item_Number（PK）和Ingredient_Number（PK）列的输入数据，就会自动更改我的程序以检查和更新Production_Cost

Answer 1

这是一个解决方案，它只会查询您需要更新的内容，然后使用批量更新它们。它会表现得相当不错。

CREATE OR REPLACE update_pr_costs
AS
DECLARE

    menu_item_tab IS TABLE OF ROWTYPE%MENU_ITEM
        INDEX BY PLS_INTEGER;

    menu_items menu_item_tab;

Begin

Select
    mi.Menu_Item_Number,
    mi.Menu_Item_Name,
    mi.Current_Price,
    (mii.Quantity_Needed * ig.Current_Cost * 0.75) Production_Cost
BULK COLLECT INTO menu_items
FROM Menu_Item_Ingredient mii
JOIN Ingredient ig
ON mii.Ingredient_Number = ig.Ingredient_Number
LEFT JOIN Menu_Item mi
ON mi.Ingredient_Number = ig.Ingredient_Number
AND mii.Menu_Item_Number = mi.Menu_Item_Number
WHERE (ig.Current_Cost * mii.Quantity_Needed * 0.75) > mi.Production_Cost;

FORALL i in menu_items.FIRST .. menu_items.LAST
    UPDATE Menu_Item
    SET Production_Cost = menu_items(i).Production_Cost
    where Menu_Item_Number = menu_items(i).Menu_Item_Number
    AND Ingredient_Number = menu_items(i).Ingredient_Number; 


End PR_Check_Cost;/
SHOW ERRORS;

可用于启动程序的触发器。

CREATE OR REPLACE TRIGGER ingredient_after_update
AFTER UPDATE
   ON Ingredient
BEGIN
   update_pr_costs;
END;

CREATE OR REPLACE TRIGGER menu_item_ing_after_update
AFTER UPDATE
   ON Menu_Item_Ingredient
BEGIN
   update_pr_costs;
END;

检查Oracle上产品成本的过程

1 个答案: