How should I seed data to many to many relation in Entity Framework Code first 5.0

问题

I am having my first steps in EF 5.0 I have a many to many relationship. Movie can Have multiple Types and Type can have multiple Movies

public class Movie
{
    public int MovieId { get; set; }
    [Required]
    public string Name { get; set; }

    public virtual ICollection<Type> Types { get; set; }
}


public class Type
{
    public int TypeId { get; set; }
    public string MovieType { get; set; }

    public virtual ICollection<Movie> Movies { get; set; }
}

When I generated the Database it creates many-to-many between Movie and type

So, What should i do to seed this many to many table? I tried many solution posted here but it didn't works.

Also, is this the best way to Generate a Many-To-Many Relation using EF code first

回答1:

Just create a few movies and a few types and create relationships by adding some of those types to the Movie.Types collection (or the other way around), for example:

protected override void Seed(MyContext context)
{
    var movie1 = new Movie { Name = "A", Types = new List<Type>() };
    var movie2 = new Movie { Name = "B", Types = new List<Type>() };
    var movie3 = new Movie { Name = "C", Types = new List<Type>() };

    var type1 = new Type { MovieType = "X" };
    var type2 = new Type { MovieType = "Y" };

    movie1.Types.Add(type1);

    movie2.Types.Add(type1);
    movie2.Types.Add(type2);

    movie3.Types.Add(type2);

    context.Movies.Add(movie1);
    context.Movies.Add(movie2);
    context.Movies.Add(movie3);
}

来源：https://stackoverflow.com/questions/14183163/how-should-i-seed-data-to-many-to-many-relation-in-entity-framework-code-first-5