Product must paid?
Hello, I have 3 tables, Customer----< invoice----< Item_pay >----Product
Customer::Customer_PK ----< Invoice::Customer_FK
Invoice::Inv_PK ----< Item_pay::invoice_FK
Product::Prod_PK ----< Item_pay::Product_FK
Customers can purchase several times on different bills.
I can know the number of bills he paid during the year. I want to know for each Client what products he buy more.
How can i do this? Please any help is welcome!