实体框架的包含和选择是其他一些实体

Question

I am using Entity Framework 6 latest stable version with Northwind database. And I wrote a query like below. Even I didn't include customer to order. And also included entity OrderDetails has Order (this is like recursion). And the final included entity Product of OrderDetails has Category even I didn't include. The weird thing is Supplier is a navigation property but it is null for product.

Plus : LazyLoading and ProxyCreationEnabled is false

var orders = Context.Orders
            .Include(i => i.Order_Details)
            .Include(i => i.Order_Details.Select(a => a.Product))
            .Where(i => i.EmployeeID == employeeId && i.CustomerID == customerId)
            .ToList();

And OrderDetail's issue

What I can't catch on this?

Answer 1

you can put a select if you dont want unwanted data from table.you can do by anonymous select or using view-model Class

 var orders = Context.Orders
            .Include(i => i.Order_Details)
            .Include(i => i.Order_Details.Select(a => a.Product))
            .Where(i => i.EmployeeID == employeeId && i.CustomerID == customerId)
            .Select new
             {
                //here you can select the fields which all are you required
             }

or

            .Select new requireddatavm
             {
                //here you can select the fields which all are you required
             }

In method syntax, with other operators:

.Where(i => i.EmployeeID == employeeId && i.CustomerID == customerId)

, returns the whole row including included fields