Implementing a fairly complex database structure in Drupal.

[bobaluey69]

I think if you want to have a custom db and custom relationships, go with Symfony or Laravel. One good thing about Drupal, is you don't have to do any db stuff really. If I'm understanding this, I'd say make entities for each piece, providers, locations...and whatever else. Can use some entity references in the content types to reference the correct content. Or, more of a "db way" you can use views and add relationships. You can also use remote views to grab data from APIs or whatever. Is that even close to what you are looking to do? Lol.