public bool SaveTeacher(TeacherDTO dto) { using (var ctx = new SMSContext()) { if (dto.TID > 0) { //Update var query = from p in ctx.Teachers where p.TID == dto.TID select p; //Now query will be executed on DB and will return result var result = query.FirstOrDefault(); if (result != null) { result.Name = dto.Name; result.Subject = dto.Subject; } } else { ctx.Teachers.Add(dto); } ctx.SaveChanges(); } return true; }