1
I’m having trouble mapping the category within a product, when I list the products in the category (virtual class) comes empty, even with CategoryId filled.
Product
public class Product
{
    public Product()
    {
        this.LastUpdate = DateTime.Now;
    }
    public int Id { get; set; }
    public string Title { get; set; }
    public decimal Price { get; set; }
    public DateTime LastUpdate { get; set; }
    public int CategoryId { get; set; }
    public virtual Category Category { get; set; }
    public override string ToString()
    {
        return this.Title;
    }
}
Product Map
public class ProductMap : EntityTypeConfiguration<Product>
{
    public ProductMap()
    {
        ToTable("Product");
        HasKey(x => x.Id);
        Property(x => x.Title).HasMaxLength(160).IsRequired();
        Property(x => x.Price).IsRequired();
        Property(x => x.LastUpdate).IsRequired();
        HasRequired(x => x.Category);
    }
}
Category
public class Category
{
    public int Id { get; set; }
    public string Title { get; set; }
    public ICollection<Product> Products { get; set; }
    public override string ToString()
    {
        return this.Title;
    }
}
Category Map
public class CategoryMap : EntityTypeConfiguration<Category>
{
    public CategoryMap()
    {
        ToTable("Category");
        HasKey(x => x.Id);
        Property(x => x.Title).HasMaxLength(60).IsRequired();
        HasMany<Product>(x => x.Products).WithRequired(c => c.Category);
    }
}
Getproducts
// GET: api/Product
public IQueryable<Product> GetProducts()
{
    db.Configuration.ProxyCreationEnabled = false;
    return db.Products;
}
Return
{
    "Id": 1,
    "Title": "Produto Eletrônico",
    "Price": 10010,
    "LastUpdate": "2015-10-29T18:28:19.547",
    "CategoryId": 1,
    "Category": null
}
						
In Categorymap, remove Hasmany and in productMap, switch to Hasrequired(x => x.Category). Withmany(x => x.Products). Hasforeignkey(x => x.Categoryid);
– Vinícius
Solved the problem?
– Renan