Migrations create and modify the database tables Teiserver needs to function.

Usage

To use migrations in your application you'll need to generate an Ecto.Migration that wraps calls to Teiserver.Migration:

mix ecto.gen.migration add_teiserver
copy

Open the generated migration in your editor and call the up and down functions on Teiserver.Migration:

defmodule MyApp.Repo.Migrations.AddTeiserver do
  use Ecto.Migration

  def up, do: Teiserver.Migrations.up()

  def down, do: Teiserver.Migrations.down()
endcopy

This will run all of Teiserver's versioned migrations for your database.

Now, run the migration to create the table:

mix ecto.migrate
copy

Migrations between versions are idempotent. As new versions are released, you may need to run additional migrations. To do this, generate a new migration:

mix ecto.gen.migration upgrade_Teiserver_to_v1
copy

Open the generated migration in your editor and call the up and down functions on Teiserver.Migration, passing a version number:

defmodule MyApp.Repo.Migrations.UpgradeTeiserverToV1 do
  use Ecto.Migration

  def up, do: Teiserver.Migrations.up(version: 1)

  def down, do: Teiserver.Migrations.down(version: 1)
endcopy

Isolation with Prefixes

Teiserver supports namespacing through PostgreSQL schemas, also called "prefixes" in Ecto. With prefixes your jobs table can reside outside of your primary schema (usually public) and you can have multiple separate job tables.

To use a prefix you first have to specify it within your migration:

defmodule MyApp.Repo.Migrations.AddPrefixedTeiserverJobsTable do
  use Ecto.Migration

  def up, do: Teiserver.Migrations.up(prefix: "private")

  def down, do: Teiserver.Migrations.down(prefix: "private")
endcopy

The migration will create the "private" schema and all tables, functions and triggers within that schema. With the database migrated you'll then specify the prefix in your configuration:

config :my_app, Teiserver,
  prefix: "private",
  ...copy

In some cases, for example if your "private" schema already exists and your database user in production doesn't have permissions to create a new schema, trying to create the schema from the migration will result in an error. In such situations, it may be useful to inhibit the creation of the "private" schema:

defmodule MyApp.Repo.Migrations.AddPrefixedTeiserverJobsTable do
  use Ecto.Migration

  def up, do: Teiserver.Migrations.up(prefix: "private", create_schema: false)

  def down, do: Teiserver.Migrations.down(prefix: "private")
endcopy

Migrating Without Ecto

If your application uses something other than Ecto for migrations, be it an external system or another ORM, it may be helpful to create plain SQL migrations for Teiserver database schema changes.

The simplest mechanism for obtaining the SQL changes is to create the migration locally and run mix ecto.migrate --log-migrations-sql. That will log all of the generated SQL, which you can then paste into your migration system of choice.