This would indeed be very nice for brownfield projects, or spinning up an API for an existing app. If you are interested in creating a generator, the Endo project would give you a good boost by providing DB introspection.

Ecto schemas are not guaranteed to be 1:1 with database table structure (this is done by design to avoid coupling), hence why when we run migrations, we use the explicit approach for creating a table:

defmodule MyRepo.Migrations.AddWeatherTable do
  use Ecto.Migration

  def change do
    create table("weather") do
      add :city,    :string, size: 40
      add :temp_lo, :integer
      add :temp_hi, :integer
      add :prcp,    :float

      timestamps()
    end
  end
end

As you can see there are zero references to the underlying schema that will be using this table.

Taking this in consideration, I’m not entirely sure what value such a tool would have, even if you had to integrate with a new database, the time spent on initial creation of schemas would not be that long.

While I understand the benefits, building such a tool might not be that trivial, especially if you expect the relations to be determined too.

I think it could be an interesting project for someone trying to learn how to play with generators, but the value it would bring would not be that great sadly, as creation of schemas in mass is not something you do often.

This implies that you need all those schemas out of the gate, otherwise you can create and improve the schemas iteratively, this is what I usually do and it works like a charm.