Updating one table when Insert in other table

[pashi]

Hi,

I am having two tables Stock and OrderIssue as follow

Stock
ItemID, ItemName , Qty ,
1 , a , 50 ,
2 , b, 50,
3 , c , 50 ,


OrderIssue

OrderID, ItemID, Qty,
1 , 1, 5,
2 , 2, 22,
3 , 1 , 20,



After Inserting order 1 with Qty 5 in Item 1 then Stock Qty should be 50-5=45 for Item 1.
this should be same for each order for each Item

Please help me in designing this query using Trigger.

[mabubakarpk]

Dear use this code

 
CREATE TRIGGER [trgSale] ON [dbo].[Sale] 
FOR INSERT
AS
 
Begin
    declare @ItemID int
    declare @Qty float
 
    select @Qty=Qty,@ItemID=ItemID  from inserted
 
    update item Set Qty= isnull(Qty,0)  + @Qty where               ItemID=@ItemID
 
End