public async Task<IHttpActionResult> PostGroupDetails(GroupDetailsViewModel groupDetails)
        {
            GroupDetails newDetail = new GroupDetails()
            {
                user_id = groupDetails.user_id,
                group_id = groupDetails.group_id
            };
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            db.GroupDetails.Add(newDetail);
            await db.SaveChangesAsync();

            return CreatedAtRoute("DefaultApi", new { id = groupDetails.id }, groupDetails);
        }
        public async Task<IHttpActionResult> PutGroupDetails(int id, GroupDetails groupDetails)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

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

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

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

            return StatusCode(HttpStatusCode.NoContent);
        }