While most beginner tutorials for backend focus on MongoDB, I cannot help but feel discouraged as to the amount of people that do not recommend MongoDB if your data has any sort of relationship whatsoever.
I am making a game which I would hope to scale: but of course as most games go, game items are connected to the user that owns them (relational).
The main premise is having a User, who has a bunch of Pokemon-like cards, that they can battle/collect/trade. Each card only has one unique owner at any given time. Some battles will lower your level or raise your card level. Other times you might just straight up trade cards (transfer ownership).
This seems like a one-to-many relationship, which Mongo CAN do, but should I be using it this way? I understand in terms of write-off Mongo seems to be faster, but with so many references in documents to other documents, am I sacrificing a bit of speed with underlying performance?
Would it better to use SQL for a db instead?