“选择新”时出现IQueryable Casting错误

Question

 IQueryable<GRNDetail> selectedResults = from c in InventoryContext.GRNDetails
                              where c.ProductID == pro.ProductID && (c.Quantity - c.SoldQuantity > 0 || c.SoldQuantity.Value.Equals(null))
                              select new
                              {
                                  c.GRNDetailID,
                                  c.GRNID,
                                  c.Product,
                                  c.ProductID,
                                  c.PurchaseOrderDetail,
                                  c.PurchaseOrderDetailID,

                                  c.Quantity,
                                  c.SoldQuantity,
                                  c.Tax,
                                  c.TaxRate,
                                  c.Total,
                                  c.UnitPrice, 
                                  SaleQty = (c.Quantity - c.SoldQuantity)
                              };

Answer 1

您缺少类型：选择中的GRNDetail：
select new GRNDetail

编辑： 或者使用Select c;带回整个物体。或者，如果您只想要某些项目，也可以创建自定义类型。

您可以创建一个这样的自定义类型：使用您的SaleQty（设置为货币或双倍或任何适合您需要的数据类型：并将其用于您的结果：

 public class GRNDetailResults
    {
        public int GRNDetailID { get; set; }

        public int GRNID { get; set; }

        etc ....

        public double SaleQty { get; set; }

E.g

IQueryable<GRNDetailResults> selectedResults = from c in InventoryContext.GRNDetails
                              where c.ProductID == pro.ProductID && (c.Quantity - c.SoldQuantity > 0 || c.SoldQuantity.Value.Equals(null))
                              select new GRNDetailResults
                              {
                                 GRNDetailID = c.GRNDetailID,
                                  GRNID  =c.GRNID, 
                                   etc ...
                                  SaleQty = (c.Quantity - c.SoldQuantity)
                              };