LINQ查询语法

 LINQ查询语法：

into：可以使用 into 上下文关键字创建一个临时标识符，以便将 group、join 或 select 子句的结果存储到新的标识符中。
            var data = new List<WarehousestorageSM>();
            data = (from m in storageList
                    join S in catalogList on m.CatalogID equals S.CatalogID into Stemp
                    from SS in Stemp.DefaultIfEmpty(new WarehousestorageSM())
                    join t in holdStorageList on new { m.CommodityID, m.ProductBatchID, m.StockType } equals new { t.CommodityID, t.ProductBatchID, t.StockType } into temp
                    from tt in temp.DefaultIfEmpty(new WarehousestorageSM())
                    join f in stockChangeList on m.CommodityID equals f.CommodityID into ftemp
                    from ff in ftemp.DefaultIfEmpty(new WarehousestorageSM())
                    select new WarehousestorageSM
                    {
                        ID = m.ID,
                        CommodityName = m.CommodityName,
                        CommodityID = m.CommodityID,
                        Stand = m.Stand,
                        isPackageBox = m.isPackageBox,
                        Style = m.Style,
                        Colour = m.Colour,
                        Size = m.Size,
                        MemberID = m.MemberID,
                        WareHouseID = m.WareHouseID,
                        BarCode = m.BarCode,
                        CommodityCode = m.CommodityCode,
                        FactAmount = m.FactAmount,
                        OperateAmount = m.FactAmount - (tt.HoldAmount) - m.LockAmount,
                        HoldAmount = tt.HoldAmount,
                        LockAmount = m.LockAmount,
                        MemberName = m.MemberName,
                        StockType = m.StockType,
                        StockTypeName = m.StockTypeName,
                        day = ff.day,
                        CatalogName = SS.CatalogName,
                        AlterStorage = m.AlterStorage,
                        AlterDiffer = m.AlterDiffer
                    }).ToList();