Configure Many-to-Many Relationships Using Fluent API

In this blog, I’ll show you how to configure Many-to-Many relationships between Order and Product entities as shown below:

Order.cs

public class Order
{
    public int OrderId
    {
        get;
        set;
    }
    public DateTime Date
    {
        get;
        set;
    }
    public int price
    {
        get;
        set;
    }
    public ICollection < Product > Products
    {
        get;
        set;
    }
    public Order()
    {
    }
}

Product.cs

public class Product
{
    public int ProductId
    {
        get;
        set;
    }
    public string ItemName
    {
        get;
        set;
    }
    public int CostPerUnit
    {
        get;
        set;
    }
    public int NumerInStock
    {
        get;
        set;
    }
    public ICollection < Order > Orders
    {
        get;
        set;
    }
    public Product()
    {
    }
}

Now, you can configure many-to-many relationships as follows:

protected override void OnModelCreating(DbModelBuildermodelBuilder)
{
    modelBuilder.Entity < Order > ()
        .HasMany < Product > (p => p.Products)
        .WithMany(o => o.Orders)
        .Map(op =>
        {
            op.MapLeftKey("OrderId");
            op.MapRightKey("ProductId");
            op.ToTable("OrderDetails");
        });
}

As you can see above, the code that I wrote will create a new table named OrderDetails with OrderId, and ProductId properties.