return (from product in db.Products
from orderedProduct in db.OrderedProducts
where orderedProduct.ProductID == product.ProductID
group orderedProduct by product into productGroups
select new
{
product = productGroups.Key,
numberOfOrders = productGroups.Count()
}
).OrderByDescending(x => x.numberOfOrders).Distinct().Take(10);
它将给您10个项目,每个项目都包含产品对象,以及numberOfOrders整数。
:
由于这将作为方法的返回值,并且由于C#不允许返回匿名类型(因此C.4.0中仍具有此功能),因此您可以将匿名类型转换为类。
创建您要返回的类型的类
public class ProductOrders
{
public ProductOrders() {
}
public Product product { get; set; }
public int numberOfOrders { get; set; }
}
并使用此查询返回该类的对象
return (from product in db.Products
from orderedProduct in db.OrderedProducts
where orderedProduct.ProductID == product.ProductID
group orderedProduct by product into productGroups
select new ProductOrders
{
product = productGroups.Key,
numberOfOrders = productGroups.Count()
}
).OrderByDescending(x => x.numberOfOrders).Distinct().Take(10);
现在的返回值为type 。