WebAPI 2返回空对象列表

Question

I have this action that is supposed to return a list of students

[HttpGet("GetAllStudentsByYear/{year}")]
public IActionResult GetAllStudentsByYear(int year)
{
    using (var db = new StudentsCFD())
    {
        List<student> stud = (from std in db.student 
                              join c in db.cppsas 
                                on std.cppsa_id equals c.cppsa_ID 
                              where c.school_yr == year 
                              select std).ToList();
        return Ok(stud);
    }
}

I am one hundred percent certain stud is not null , it has 28 objects when debugging. However my output when called looks like this.

[
  {}
]

Answer 1

Can you directly return stud? If yes then try it once. eg return stud; And if return type IActionResult gives error make it dynamic

Answer 2

adding db.Configuration.ProxyCreationEnabled = false before the linq worked. It looks like it was a circular or large referencing of foreign keys.