create table achievements
(
    userId        bigint                             not null,
    achievementId int                                not null,
    achievedAt    datetime default CURRENT_TIMESTAMP not null
);

create table achievements
(
    userId        bigint                             not null,
    achievementId int                                not null,
    achievedAt    datetime default CURRENT_TIMESTAMP not null
);

public DbSet<Achievement> Achievements { get; set; }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
   modelBuilder.Entity<Achievement>().ToTable("achievements");
} 

public DbSet<Achievement> Achievements { get; set; }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
   modelBuilder.Entity<Achievement>().ToTable("achievements");
} 

public class FactoryTree
{
  ProductionStep root;
  Recipe recipe;

  public FactoryTree(Recipe recipe)
  {
    this.recipe = recipe;
    root = new ProductionStep(recipe, 1);
  }
}

public class FactoryTree
{
  ProductionStep root;
  Recipe recipe;

  public FactoryTree(Recipe recipe)
  {
    this.recipe = recipe;
    root = new ProductionStep(recipe, 1);
  }
}

public class ProductionStep
{
  public Recipe Recipe;
  public List<ProductionStep> Children;
  public ProductionStep Parent;

  public ProductionStep(Recipe recipe, float count)
  {
    Recipe = recipe;
    Children = new List<ProductionStep>();
  }
}

public class ProductionStep
{
  public Recipe Recipe;
  public List<ProductionStep> Children;
  public ProductionStep Parent;

  public ProductionStep(Recipe recipe, float count)
  {
    Recipe = recipe;
    Children = new List<ProductionStep>();
  }
}