Thank you for the very detailed post. But you show multiple occurrences of the same table--judging by your naming conventions. Which is the basis for the layout shown? And which is the basis for the portal shown?
I want it to auto populate the Product id when the category and product are selected
If you have set up a typical conditional value list where category limits what products are listed, a value list where Product ID is the value source for the first field and product name is the value source for the second field, you can just select the product by name from the list and let the value list enter the ID for you.
I have my own shopping list app that we use for monthly family shopping trips to a "big box" store. I don't use a portal for this. I set up a list view of all products that we have previously purchased and we tap a button to select that item for the list. The button of a selected item changes appearance to show a "tick mark" to indicate that it's been selected for the upcoming shopping trip as well as adding that record to a related table in order to add it to the list (a second tap makes the tick mark disappear and deletes the related record). The user can search/sort/find records to find the item that they need to add. A different layout only lists the selected items and a new button allows us to check of each item as it is added to the shopping cart(s).
I set up this interface--with a location based sort order that both groups items by general location and orders the groups into an order that matches the typical 'path' that we take thru the store as a better way to manage this with a touch interface and the limited screen space of a smart phone.
sorry about the slow reply i left the office and went home to take a nap for a bit as ive just finished a 24 hour shift, the shopping lists are based on the shopping list table and the items when added to the portal go to the shopping list item table
I'm not asking about the name of the tables, but the table occurrences used in setting up that layout. These are the names of the "boxes" in your relationships graph and let us understand the "context" for the layout and thus give us a chance to answer your question.
You do not have any table occurrence named "Shopping List". Instead you have one named "SL_Shopping_List" and another apparent occurrence of the same table named: "SL_Shopping_List 2". Presumably, your layout is based on the first one that I named, but prefer not to make possibly incorrect assumptions.