When adding items to eCart it will not hook into your db for you. In order for the items to be added with just the id referenced you will need to add a recordset to your page that is filtered on a posted item id.
Your buttons on the page will simply post the item id back to the same page. With the page setup like this the user will select an item by clicking on it's button, then the id for that product will be submitted back to the page. Your recordset will filter based on this id.
The final part of this that makes it all work is to add this to the cart. You will want to add in an add to cart > get contents from recordset. You would then just bind the values for the cart columns to the corresponding column in your recordset.
Please post back with any questions that you have about this process and we will help you out with whatever we can.
