Hi Jesus,
That's an interesting problem. Are you looking to create this drop down box inside the CMS?
There are ways of doing it, but I'm not sure if this will be the best approach for you. The issue with having a dropdown box populated by 3 different tables, is that when you are displaying those selections on the front end of the site, you have no way of knowing from which of those 3 tables a given selection came from. So if you needed to retrieve a record based on a selection, or output a custom URL, you wouldn't be able to.
An easier approach would be to have 3 different dropdown boxes, 1 for each table. That way you can have a simple query to get the records, and will be able to easily retrieve related records if need be.
Hope this helps
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Jason Sauchuk - Project Manager
interactivetools.com
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