Creating new table with foreign key with Entity Framework Core

Question

Creating new table with foreign key with Entity Framework Core

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Question

I have a DbContext which I via the developer command prompt and creating a migrations schema turn in to my database. But if you look at the product object I have a dictionary object named Parts. That property does not get added to the Product table when the database is updated in the command prompt. I don't even know if it is possible what I am trying to do.

I want to add a table in the database named Parts and then add a foreign key to the Product table which connects the Parts dictionary object in the Product table, and the the new Parts table. Is this possible with Entity Framework Core?

public class ShoppingDbContext : IdentityDbContext<User>
{
    public ShoppingDbContext(DbContextOptions options) : base(options)
    {
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        base.OnConfiguring(optionsBuilder);
    }

    public DbSet<Product> Products { get; set; }
    public DbSet<Order> Orders { get; set; }
}

public class Product 
{
    public int ProductId { get; set; }
    public string ProductName { get; set; }
    public double Price { get; set; }
    public int CategoryId { get; set; }
    Dictionary<string, Part> Parts { get; set; }
}

Robel Haile

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Arthur Vickers · Accepted Answer · 9/21/2016 4:10:39 PM

EF Core can't currently map a dictionary property directly. If you want to create an association between Products and Parts, then define each of them as an entity. You can then create navigation properties between them--a reference from Part to the Product which it belongs, and a collection of Parts on Product. For example:

public class Product 
{
    public int ProductId { get; set; }
    public string ProductName { get; set; }
    public double Price { get; set; }
    public int CategoryId { get; set; }
    public ICollection<Part> Parts { get; set; }
}

public class Part
{
    public int PartId { get; set; }
    public int ProductId { get; set; }
    public Product Product { get; set;}
}

Part also defines a property ProductId that acts as the FK to the Product entity. You don't need to add that property--EF will simulate it for you if you don't want it, but usually it is easier to deal with entities if the FK is mapped to a property.

Creating new table with foreign key with Entity Framework Core

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