Ultimately I would like to create an external list that can be customized (i.e., partly columns from a SQL table and partly native SharePoint columns).
BCS isn't an option because it would not let me create extra columns in a SharePoint "external" list. I am a beginner programmer, but I am looking into creating a BDC model or some kind of SharePoint add-in on VS to populate SQL data into a custom SP list.
Is there code that exists for this? Or some method that already exists that can lead me through? I'm at a loss after numerous attempts and would appreciate the help.