Coming from PowerBI I'm having trouble understanding how to setup relationships in CDS. I have two files imported as custom entities, one with Accounts and one with Opportunities, each with 10k plus rows from a csv. I want to setup one-to-many between Accounts and Opportunities, as each Opportunity record has the key of an Account.
In PowerBI, there is a simple drag and drop tool to match the keys. In CDS, there appears to be something different and I don't understand how to match the existing keys in those entities.
I think I'm misunderstanding something fundamental here.
Also, can somebody explain the "Primary" and "Related" terminology when setting these up? The Microsoft documentation appears to say the terminology is reversed depending on which service you use, and it appears counterintuitive (my Account shows up as "related" not "primary", which to me is odd). Why not just call it "Many" and "One" to avoid confusion?