// PUT api/universities/{universityCode}/students/{studentId}
        public HttpResponseMessage PutStudent(string universityCode, string studentId, EIStudent student)
        {
            if (ModelState.IsValid && studentId == student.StudentId)
            {
                EIStudent existingStudent = GetStudent(universityCode, studentId);
                existingStudent.Firstname = student.Firstname;
                existingStudent.Lastname  = student.Lastname;
                //db.Entry(existingStudent).State = EntityState.Modified;

                try
                {
                    db.SaveChanges();
                }
                catch (DbUpdateConcurrencyException)
                {
                    return(Request.CreateResponse(HttpStatusCode.NotFound));
                }

                return(Request.CreateResponse(HttpStatusCode.OK));
            }
            else
            {
                return(Request.CreateResponse(HttpStatusCode.BadRequest));
            }
        }
        // GET api/universities/{universityCode}/students/{studentId}
        public EIStudent GetStudent(string universityCode, string studentId)
        {
            EIStudent student = db.Students.FirstOrDefault(s => s.EducationalInstitute.Code == universityCode && s.StudentId == studentId);

            if (student == null)
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound));
            }

            return(student);
        }
        // POST api/universities/{universityCode}/students/
        public HttpResponseMessage PostStudent(string universityCode, EIStudent student)
        {
            if (ModelState.IsValid)
            {
                student.EducationalInstitute = db.EducationalInstitutes.First(u => u.Code == universityCode);
                db.Students.Add(student);
                db.SaveChanges();

                HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.Created, student);
                response.Headers.Location = new Uri(Url.Link("StudentOfEducationalInstitute", new { universityCode = universityCode, studentId = student.StudentId }));
                return(response);
            }
            else
            {
                return(Request.CreateResponse(HttpStatusCode.BadRequest));
            }
        }
        // DELETE api/universities/{universityCode}/students/{studentId}
        public HttpResponseMessage DeleteStudent(string universityCode, string studentId)
        {
            EIStudent student = GetStudent(universityCode, studentId);

            if (student == null)
            {
                return(Request.CreateResponse(HttpStatusCode.NotFound));
            }

            db.Students.Remove(student);

            try
            {
                db.SaveChanges();
            }
            catch (DbUpdateConcurrencyException)
            {
                return(Request.CreateResponse(HttpStatusCode.NotFound));
            }

            return(Request.CreateResponse(HttpStatusCode.OK, student));
        }