>you are right. basically, i need to search to see if the invoice number exists, then i need to find out if the item code is associated with that particular item code. if it is not, then ignore it, however if it is, then take that particular item's data. would this process work for that?

Where is the table that has the item_code in it for the invoices?

We can give you a select or two that will do what you want but selects are designed to specific table structures and it is hard to tell you how to do the joins unless we know the names and structures of the tables involved.