Entity Framework newbie question

Question

I'm having trouble understanding EntityFramework

I have a table called "Categories", with columns "IdCategory,CategoryName". I have a table called "Country", with columns "IdCountry,CountryName"

I have a table called "Product" with Columns "IdProduct, IdCategory,IdCountry,ProductName"

When I create de EDM it maps all 3 entities. Product entity only have 2 scalar properties "IdProduct,ProductName" and 2 navigation Properties "Category,Country"

The problem I'm facing is when I want to create a new product

Product p = new SalesContext.Produc();
p.IdProduct = 1;
p.ProductName = "New Product";

Those are the only properties i can set. The problem is that I have to set de IdCategory and IdCountry, but those properties don't exist in Product Entity. I only have them as navigation properties.

So how can I set IdCategory and IdCountry before calling

SalesContext.AddProduct(p);
SalesContext.SaveChanges();

Please Help me!

Dev Enviroment: VS2008 sp1, .net 3.5 sp1, win 7.

Answer 1

Presuming you've correctly defined the FKs in the DB, you should have associations to the other tables, so you can change your code to:

Product p = new SalesContext.Product();
p.IdProduct = 1;
p.ProductName = "New Product";
p.Category = SalesContext.Categories.First(c => c.IdCategory == 1);
p.Country = SalesContext.Countries.First(c => c.IdCountry == 2);
SalesContext.AddProduct(p);
SalesContext.SaveChanges();