public IActionResult Post([FromBody] Tracks track)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }

            _context.Tracks.Add(track);
            try
            {
                _context.SaveChanges();
            }
            catch (DbUpdateException)
            {
                if (InventoryExists(track.TrackId))
                {
                    return(new StatusCodeResult(409));
                }
                else
                {
                    throw;
                }
            }

            return(CreatedAtRoute("GetTracks", new { id = track.TrackId }, track));
        }
        public IActionResult Post([FromBody] LastOneUsers user)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }


            var existingUser = from u in _context.LastOneUsers
                               where u.Username == user.Username
                               select u;

            if (existingUser.Count <LastOneUsers>() > 0)
            {
                return(new StatusCodeResult(StatusCodes.Status409Conflict));
            }


            _context.LastOneUsers.Add(user);

            try
            {
                _context.SaveChanges();
            }
            catch (DbUpdateException)
            {
                if (UserExists(user.UserId))
                {
                    return(new StatusCodeResult(StatusCodes.Status409Conflict));
                }
                else
                {
                    throw;
                }
            }

            return(CreatedAtRoute("GetUser", new { id = user.UserId }, user));
        }