Self-referencing many-to-many recursive relationship code first Entity Framework

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By convention, Code First will take uni-directional associations as one to many. Therefore you need to use fluent API to let Code First know that you want to have a many to many self referencing association:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Member>().HasMany(m => m.Friends).WithMany().Map(m =>
        {
            m.MapLeftKey("MemberId");
            m.MapRightKey("FriendId");
            m.ToTable("MembersFriends");
        }
    );
}

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