我怎麼能在LINQ使用 「COALESCE（SUM ......」

Question

我嘗試使用和與凝聚我怎麼能轉化爲LINQ

SELECT @SumQtyOut=COALESCE(SUM(Qty),0) FROM dbo.StockMovement WHERE FromLocationType=@FromLocationType AND 
     * FromNo=@FromNo AND FromSeq=@FromSeq AND ItemTypeNo=@ItemTypeNo AND ItemID=@ItemID

我做sometihng：

using (StockProcedureDataContext stock = new StockProcedureDataContext()) 
       { 
        SumQtyOut = from s in stock.StockMovements 
           where s.FromLocationType == FromLocationType && 
           s.FromNo== FromNo && 
           s.FromSeq == FromSeq && 
           s.ItemTypeNo == ItemTypeNo && 
           s.ItemID == ItemID select 
       }

Answer 1

該段應得到你正在尋找的結果。

using (StockProcedureDataContext stock = new StockProcedureDataContext()) 
{ 
    var items = from s in stock.StockMovements 
       where s.FromLocationType == FromLocationType && 
       s.FromNo== FromNo && 
       s.FromSeq == FromSeq && 
       s.ItemTypeNo == ItemTypeNo && 
       s.ItemID == ItemID 
       select s.Qty ?? 0; 
    SumQtyOut = items.Sum(x => x); 
} 

select s.Qty ?? 0返回0，如果s.Qty是null。 items.Sum(x => x)總結您選擇的數量。