public RelationshipsStudentSubject Update(RelationshipsStudentSubject relationships)
        {
            var r = _db.RelationshipsStudentSubject.Where(r => r.ID == relationships.ID).SingleOrDefault();

            if (r == null)
            {
                return(null);
            }

            r.SubjectID = relationships.SubjectID;
            r.StudentID = relationships.StudentID;

            _db.SaveChanges();

            return(r);
        }
 public int Insert(RelationshipsStudentSubject relationships)
 {
     _db.RelationshipsStudentSubject.Add(relationships);
     return(_db.SaveChanges());
 }