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如何在Linq中使用“coalesce(sum…”?

linq visual-studio .net c#

0

loki · 技术社区 · 16 年前

我试着用和合并。如何翻译成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

我做了一些事情:

 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 
                }

1 回复 | 直到 16 年前

1

0

AxelEckenberger 16 年前

这段代码应该产生您正在寻找的结果。

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) 汇总您选择的数量。