linq-to-entities - 为什么 linq to entities 不支持这个查询？

Question

我有这样的查询。

var query = from o in _context.Orders
            join c in _context.Customers on o.CustomerId equals c.CustomerId
            orderby o.ShippedDate descending
            select new {OrderId = o.OrderId, Customer = c.FirstName};

我收到错误“仅支持初始值设定项、实体成员和实体导航属性”。我发誓我之前已经能够做到这一点，但对于我的生活来说，我无法理解问题所在。我也无法像这样重构查询。

var query = from o in _context.Orders
            orderby o.ShippedDate descending
            select new {OrderId = o.OrderId, Customer = o.Customer.FirstName};

困惑。

Answer 1

试试这个:

var query = from o in _context.Orders
            join c in _context.Customers on o.CustomerId equals c.CustomerId
            orderby o.ShippedDate descending
            select new {o.OrderId, c.FirstName};