Copies of tables - without navigation?

[patrykdawid]

Friends!
I need to turn off the navigation, but the rest of the action is to remain the same, e.g. a column containing a foreign key must be created. I want to achieve similar behavior as Envers for nHibernate (https://github.com/nhibernate/nhibernate-envers) - data copy per table but without navigation.

Is it possible? It's great if you could show an example in the code...

EF Core version:
Database provider: Pomelo.EntityFrameworkCore.MySql
Target framework: .NET Core 3.1 or .NET 5.0

[ajcvickers]

@patrykdawid Here's an example of configuring a relationship without navigations. We will add this to the docs.

public class Blog
{
    public int Id { get; set; }
    public string Name { get; set; }
}

public class Post
{
    public int Id { get; set; }
    public string Content { get; set; }

    public int? BlogId { get; set; }
}

public class SomeDbContext : DbContext
{
    public DbSet<Blog> Blogs { get; set; }
    public DbSet<Post> Posts { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder.UseSqlServer(Your.ConnectionString);

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Blog>(e => e.HasMany<Post>().WithOne());
    }
}

This maps to the following tables in SQL Server:

      CREATE TABLE [Blogs] (
          [Id] int NOT NULL IDENTITY,
          [Name] nvarchar(max) NULL,
          CONSTRAINT [PK_Blogs] PRIMARY KEY ([Id])
      );

      CREATE TABLE [Posts] (
          [Id] int NOT NULL IDENTITY,
          [Content] nvarchar(max) NULL,
          [BlogId] int NULL,
          CONSTRAINT [PK_Posts] PRIMARY KEY ([Id]),
          CONSTRAINT [FK_Posts_Blogs_BlogId] FOREIGN KEY ([BlogId]) REFERENCES [Blogs] ([Id]) ON DELETE NO ACTION
      );