Question

I am trying to display two values in a entity by using two foreign keys.

I have three tables; one of table is Product table.

Two tables are Category and Model for displaying these value ‘name’, and ‘modelName’.

When I use LINQ, I was using this coding before adding the Model entity.

var product = from a in db.Product.Include(a => a.Category)
                      select a;

How can I add Model entity in here?

such as

var product = from a in db.Product.Include(a => a.Category, a => a.Model)
                      select a;

Is it possible to write?

Here is my models.

--Prodruct.cs--

public class Product
{
    [Key] public int productId { get; set; }

    [Required(ErrorMessage = "Please select category")]
    public int categoryId { get; set; }

    [Required(ErrorMessage = "Please select model")]
    public int modelId { get; set; }

    [DisplayName("Model name")]
    public String model { get; set; }

    public virtual Category Category { get; set; }
    public virtual Model Model { get; set; }
}

--Category.cs--
public class Category
{
    [Key] public int categoryId { get; set; }
    public String name { get; set; }
}

--Model.cs--
public class Model
{
    [Key] public int modelId { get; set; }
    public String name { get; set; }
}

--RentalDB.cs--
public class rentalDB : DbContext
{
    public DbSet<Product> Product { get; set; }
    public DbSet<Model> Model { get; set; }
    public DbSet<Customer> Customer { get; set; }
    public DbSet<Order> Order { get; set; }
    public DbSet<Cart> Cart { get; set; }
    public DbSet<Category> Category { get; set; }
    public DbSet<OrderDetails> OrderDetails { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
    }
}

Please let me know how to put inner join(?) in LINQ.

Thank you.

Answer 1

I think you might want the following since Include returns IQueryable:

var product = from a in db.Product.Include(a => a.Category).Include(a => a.Model)
                  select a;