public ActionResult Put([FromBody] UserAchievement changedItem) { if (changedItem is null) { return(BadRequest()); } var existingItem = _UserAchievementService.AsQueryable() .Where(x => x.Id == changedItem.Id) .FirstOrDefault(); if (existingItem is null) { return(NotFound()); } var item = _UserAchievementService.UpdateUserAchievement(existingItem, changedItem); return(Ok(item)); }