php query doubt

[jeremy jacob]

i have two tables in a single database sales... one is product other is order... i want someones help to know how can i do one operation.... i.e

when i click on order i want to subtract that one order from the product table....

can u help me with the query?

ok sure..

Order table

Id int
Product_id text
Dealer text
Quantity int

Product

Id int
Name text
Brand text
Expirydate date
Mfgdate date
Department text
Cost int
Quantity int

[Ammu]

Better you write a trigger at back end.

update product set Quantity=Quantity-new.Quantity where Product.Id=new.Id