No nested results in Entity Framework Core [duplicate]

Answer 1

It's not magic the DbContext won't download entities from the DB until you not tirgger that. When you clicked on the context.Groups Results View in debugging, the DbContext gets all the Groups from the DB so after that it can associate to the users.

I think you are searching for the Include method where you can get the users with the associated groups in one query like this:

var allUsers = context.Users.Include(u => u.Groups).ToList();

Answer 2

This behavior comes from the laziness of loading entities.

By default, you have to manually load each of sub-entity. It is called eager-loading.

In order to eager-load your entities, you have to use the .Include() method on each of your navigation properties.

e.g. context.User.Include(x => x.Groups)

The Include method generates a new SQL statement to retrieve your Groups from database.

Then you can use the ToList() method to force executing your query.

Answer 3

Looks like you are lazy loading the entities.

You can eager load them by using .Include.

 var allUsers = context.Users.Include(user => user.Groups).ToList();

This approach loads the first entity (Users) as well as the related entities as part of the query (Groups).