Please Help !
I made a access db with following tables:
Producs
Orders
OrderDetails
Customers
I can't update the stock field of products table when input a new order from orders form. For Example
I have a stock of 15 pcs for a product.A customer orders 5 pcs of this product.I am searching a way so when I input this order (in orders form) the stock field of table Products updates to 10 pcs(15-5)
I tried several ways to solve this problem (Vba ,Sql) but nothing.
I appreciate if you help me
Thank you in advance
P.S. If this help I can tell you more details or send a demo of my db

Suspect that the record you are trying to update is a result of a join of tables where there Primary and Foreign keys are not truly unique and thus can't update.

Suggest that you run a UPDATE query using the unique index of the record in the OrderDetails table only.

Cheers Ray

update table Products from trigger for update on OrderDetails table:
 minus stock Products where Orderdetail.ProductID = inserted.ProductID

and plus from trigger for delete.