EF CF手动配置多对多映射

Question

我有一个现有的数据库.目前我正在尝试使用实体框架代码将新的Entity对象映射到该DB.以下是具有朋友集合的User类.正如您所看到的,这是与同一个表的多对多关系.如何将此关系映射到具有"user_id"和"friend_id"列的表"user_friend".

public class User
{
    private ICollection<User> _friends = new List<User>();
    public ICollection<User> Friends { get{return _firends;} }
}

moduleBuilder.Entity<User>().HasMany????.ToTable("user_friend");

Answer 1

您需要下拉到流畅的API:

public class User
{
    public int UserId { get; set; }
    public ICollection<User> Friends { get; set; }
}

public class Context : DbContext
{
    public DbSet<User> Users { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<User>().HasMany(u => u.Friends).WithMany().Map(c =>
        {
            c.MapLeftKey(u=>u.UserID, "user_id");
            c.MapRightKey(f=>f.FriendID, "friend_id");
            c.ToTable("user_friend");
        });
    }
}