实体框架5方法查询汇总

Question

我想通过查询SaleConfirmation表来获取已确认/定稿购买的摘要，但是方法语法查询让我感到很困难。

数据库表
以下是存储已完成销售的SaleConfirmation表结构。

Id   OfferId   ProdId      Qty    SaleDate
-------------------------------------------------------
10   7         121518      150    2013-03-14 00:00:00.000
19   7         100518      35     2013-03-18 14:46:34.287
20   7         121518      805    2013-03-19 13:03:34.023
21   10        131541      10     2013-03-20 08:34:40.287

• Id: 唯一行标识。
• OfferId: 外键，链接到 Offer/Sale 表。
• ProdId: 产品在产品表中的ID。
• Qty: 销售给客户的数量。
• SaleDate: 销售完成的日期。

控制器操作

var confRollUps = db.SaleConfirmation
                  .GroupBy(c => c.OfferId) // Ensure we get a list of unique/distinct offers
                  .Select(g => g.Select(i => new {
                            i.OfferId, 
                            i.Product.Variety, // "Category" of product, will be the same across products for this offer. i.Product is a SQL Server Navigation property.
                            i.Offer.Price, // The price of the product, set per offer. i.Offer is a SQL Server Navigation property.
                            i.Offer.Quantity, // The quantity of items that are expected to be sold before the offer expires
                            i.Offer.DateClose, // Date of when the offer expires
                            g.Sum(ii => ii.Qty) // Sum up the Qty column, we don't care about ProdIds not matching
                   }));

选择查询中的错误是g.Sum(ii => ii.Qty)，错误如下所示。

无效的匿名类型成员声明器。匿名类型成员必须使用成员赋值、简单名称或成员访问来声明。

- Jason Harris

Answer 1

你只需要将匿名类型分配给一个变量，试试这个。

var confRollUps = db.SaleConfirmation
              .GroupBy(c => c.OfferId) // Ensure we get a list of unique/distinct offers
              .Select(g => g.Select(i => new {
                        OfferId = i.OfferId, 
                        ProductVariety = i.Product.Variety, // "Category" of product, will be the same across products for this offer. i.Product is a SQL Server Navigation property.
                        OfferPrice = i.Offer.Price, // The price of the product, set per offer. i.Offer is a SQL Server Navigation property.
                        OfferQty = i.Offer.Quantity, // The quantity of items that are expected to be sold before the offer expires
                        OfferDateClose =i.Offer.DateClose, // Date of when the offer expires
                        Total =g.Sum(ii => ii.Qty) // Sum up the Qty column, we don't care about ProdIds not matching
               }));

- Overmachine