public IActionResult CreateUni(int universityId, [FromBody] StudentDto studentDto) { var university = _db.Universities.SingleOrDefault(u => u.UniversityId == universityId); if (university == null) { return(BadRequest("University not found!")); } var student = studentDto.ToDb(); if (student == null) { return(BadRequest("Invalid student!")); } student.University = university; _db.Students.Add(student); _db.SaveChanges(); return(Ok()); }