You don't access content for the platform directly via the database. You load data either via injecting the IContentLoader/IContentRepository or if you're on the DXP the correct way of searching for datasets would be using Search & Navigation the cloud based elastic solution that Optimizely provides for indexing and searching content.
Lets say i want to display 10 most recent articles. I would ussually have service that gets the articles sorts pass in the view model etc. How can i do it with epi server? There are no entitites that refference table how is data even saved? How do you get the dbContext?