[linq] join

[Alice52]

• inner join and group

  (from gameType in _gameTypeRecordRepository.Table
  join shape in _shapeRecordRepository.Table on gameType.ShapeName equals shape.ShapeName
  join area in _bettingAreaRepository.Table on shape.Id equals area.ShapeRecord.Id
  join spot in _bettingSpotRepository.Table on area.Id equals spot.BettingAreaRecord.Id
  where spot.IsVirtual == false
  group new { gameType.GameCode, gameType.GameName, shape.ShapeName } by new { gameType.GameCode, gameType.GameName, shape.ShapeName } into g
  select new GamingCode
  {
  GameCode = g.Key.GameCode,
  GameName = g.Key.GameName,
  ShapeName = g.Key.ShapeName,
  BettingSpotCount = g.Count()
  }).ToList<GamingCode>();

• left join

[Alice52]

• group sum and collect to Dictionary

Dictionary<int?, double> dataDic = new Dictionary<int?, double>();
dataDic = item.RecordDetail
            .GroupBy(p => p.ApplicationPeriodStartTime?.Month)
            .ToDictionary(g => g.Key, g => g.Sum(p => p.RealOverTimeNum));