public async Task <IActionResult> DelTeam(int Id)
{
var gameId = _context.SubGames.Single(g => g.ID == Id).GameID;
var delSubgame = _context.SubGames.Single(g => g.ID == Id);
var updateSubgames = _context.SubGames.Where(t => t.GameID == delSubgame.GameID && t.Round > delSubgame.Round);
foreach (var us in updateSubgames)
{
us.Round--;
}
//_context.Update(updateSubgames); //필요업음
_context.Remove(delSubgame);
await _context.SaveChangesAsync();
return(RedirectToAction(nameof(Index), new { Id = gameId, game = delSubgame.Round > 1? --delSubgame.Round : 1 }));
}