public async Task<IHttpActionResult> PutTeacherCourse(int id, TeacherCourse teacherCourse)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != teacherCourse.TeacherCourseId)
            {
                return BadRequest();
            }

            db.Entry(teacherCourse).State = EntityState.Modified;

            try
            {
                await db.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!TeacherCourseExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.NoContent);
        }
        public async Task<IHttpActionResult> PostTeacherCourse(TeacherCourse teacherCourse)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            db.TeacherCourses.Add(teacherCourse);
            await db.SaveChangesAsync();

            return CreatedAtRoute("DefaultApi", new { id = teacherCourse.TeacherCourseId }, teacherCourse);
        }