统计订单中某物品的销售总计

测试数据库设计如图：

 

实现代码如下：

 

                IQueryable<Order> orders = edm.Order;
                var tmpGroup = orders.GroupBy(p => p.OrderName);

                var abc = (from n in tmpGroup
                          from m in n
                          select new
                          {
                              Name=n.Key,
                              Count=n.Count(),
                              Sum = n.Sum(p => p.OrderDetail.Sum(c => c.Price))
                          }).Distinct();
                foreach (var item in abc)
                {
                    Console.WriteLine(item.Name.Trim() +"  "+item.Count+"  : " + item.Sum);
                }

 效果如图：