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从ef select返回tuple

linq-to-entities entity-framework .net c#

17

Felipe Pessoto · 技术社区 · 15 年前

如何使用EF4在select检索元组?

        var productCount = (from product in context.products
                    select new Tuple<Product, int>(product, products.Orders.Count));

或

        var productCount = (from product in context.products
                    select Tuple.Create(product, products.Orders.Count));

实体框架说,第一种情况下不能使用非空的构造函数,也不能识别tuple.create方法。

2 回复 | 直到 9 年前

1

20

Marc Gravell 15 年前

如何切换到Linq到投影的对象:

var productCount = from product in context.products
                select new {Product = product, Count = products.Orders.Count };
var final = from item in productCount.AsEnumerable()
            select Tuple.Create(item.Product, item.Count);

2

0

Aaron Stainback 14 年前

尝试

 var productCount = from product in context.products 
                    select new { product, Count = products.Orders.Count };

这将返回一个非常接近元组的匿名类型 http://msdn.microsoft.com/en-us/library/bb738512.aspx