Multiple 1 : 0, 1 or many, but only one 1 : 1 or many

Apologies; I believe I've answered my own question (the way I envision this working, I don't have to worry). In any case, since I can't delete this post, I'll leave it here.

I have line items that will have a 1 : 0, 1, or many relationship between an order line item table and an asset table (the latter contains much more information about the item, after acquisition), i.e., if I order a hammer, there will be a field in the line item table where I can choose (via a pulldown) hardware, or software, etc., as a line item type. The line item then have a 1 : 1 or many relationship to the record in the appropriate 'type' table.

If the line item table has a 1 : 0, 1, or many relationship with each of the asset tables, I just wondering if I need to take any programatic precautions so that each line item can only have a valid relationship to one asset table.

I realize this may sound a bit cryptic. Here's more:

A line item record is filled out with quantity, unit of measurement, price, etc., and vendor part number, generic description, etc. Upon finalizing the order, a script creates an asset record in the appropriate table, and then duplicates it x times based on the quantity. Once the asset records are created, they relate back to the line item record, but are otherwise decoupled. In other words, I want to be able to modify the asset records without affecting the historical line item information.

thanks,

Bob