How to spit Ecto Migrations into partials? - phoenix-framework

Question

I have many migration files using the same column names name, address, phone, etc.
In my migrations, I want to make a partial that calls them instead of writing it over and over:
defmodule App.Repo.Migrations.CreateUsers do
use Ecto.Migration
def change do
create table(:settings) do
add :blah, :string
App.Repo.Migrations.Common.stuff
defmodule App.Repo.Migrations.Common do
def stuff do
add :name, :string
add :address, :string
add :phone, :string
But I get an error (UndefinedFunctionError) function App.Repo.Migrations.Common.stuff/0 is undefined.stuff
What's the proper way to split migrations? In Rails this was done with require_relative

Answer 1

I can guess you put the file common.ex inside priv/repo/migration which is not included while compilation
for this to work you need 2 things:
move this file common.ex inside lib/, in order to be compiled and loaded.
add this line use Ecto.Migration above def stuff do, for the definition of add() to be imported.

Answer 2

You can define a function, just like timestamps/1 :
def timestamps(opts \\ []) when is_list(opts) do
opts = Keyword.merge(Runner.repo_config(:migration_timestamps, []), opts)
opts = Keyword.put_new(opts, :null, false)
{type, opts} = Keyword.pop(opts, :type, :naive_datetime)
{inserted_at, opts} = Keyword.pop(opts, :inserted_at, :inserted_at)
{updated_at, opts} = Keyword.pop(opts, :updated_at, :updated_at)
if inserted_at != false, do: add(inserted_at, type, opts)
if updated_at != false, do: add(updated_at, type, opts)
end