一次查询导出的优化

          result.ForEach(item =>
                 {
                // 省略一部分，简单的判断和赋值
                var trackingList = wobTrackingList.Where(m => m.WOBShipOrderID == item.OrderId);
    if (trackingList.IsStrictSafed())
                {
                    item.ParentTrackingNo = trackingList.FirstOrDefault(m => m.IsParentTrackingNo)?.TrackingNo;
                    var trackNos= trackingList.Where(m => !m.IsParentTrackingNo).Select(m=>m.TrackingNo);
                    item.TrackingNo = string.Join(",", trackNos);
                }
              // 省略一部分，简单的判断和字典中取值。

            // 省略一部分，字符序列化成对象然后取值赋值。前面优化后，进行测试，证明这里也不影响处理速度。
            });

                var trackingDic = new Dictionary<Guid, (string parentTrackingNo, string trackNos)>();
                wobTrackingList.GroupBy(m => m.WOBShipOrderID).ToList().ForEach(t => {
                    var parentTrackingNo = t.FirstOrDefault(m => m.IsParentTrackingNo)?.TrackingNo;
                    var trackNos = string.Join(",", t.Where(m => !m.IsParentTrackingNo).Select(m => m.TrackingNo));
                    trackingDic.Add(t.Key, (parentTrackingNo, trackNos));
                });

              result.ForEach(item =>
                     {
                        if (trackingDic.ContainsKey(item.OrderId))
                        {
                            var (parentTrackingNo, trackNos) = trackingDic[item.OrderId];
                            item.ParentTrackingNo = parentTrackingNo;
                            item.TrackingNo = trackNos;
                        }
                });