Question

Is there a way to tamper with the DbContext in order to auto eager load a specific Navigation property when the entity is requested in a query? (no lazy loading).

Entity Framework 5

Example:

var supremeEmployee = context.Employees.FirstOrDefault(x => x.EmployeeId == 42);

and the returned model would come back pre-populated with the “Department” navigation property.

Answer 1

Depends on what your model looks like. If you’re using interfaces or inheritance you could add a function to your DbContext class with a generic constraint on that type that always includes the navigation property.

In my experience though you’re usually better off not doing that, performance wise. I prefer to load into anonymous types just the fields i need in the moment.

In the most basic way you could do this:

public class Department
    {
        public int Id { get; set; }
    }

    public class Employee
    {
        public int Id { get; set; }
        public Department Department { get; set; }
    }

    public class MyContext : DbContext
    {
        protected DbSet<Employee> Employees { get; set; }

        public IQueryable<Employee> LoadEmployees()
        {
            return Employees.Include(p => p.Department);
        }
    }