# `Chime.Migrations`
[🔗](https://github.com/hattoriai/chime/blob/v0.1.0-dev/lib/chime/migrations.ex#L1)

The tables of Chime, in a migration of the app.

    $ mix chime.gen.migration

writes a migration that pins the latest version:

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

      def up, do: Chime.Migrations.up(version: 1)
      def down, do: Chime.Migrations.down(to: 0)
    end

The versions are `PhoenixMountable.Migrations`: tracked in the app's
database (per prefix), and run on PostgreSQL and on SQLite. A later
version of Chime that changes the tables has a new version;
`mix chime.gen.migration` then writes the migration that upgrades.

The tables (version 1):

  * `chime_events` - each call of `Chime.notify/3`, once, with its data;
  * `chime_notifications` - each person's notifications: the feed, and
    what the deliveries hang from;
  * `chime_deliveries` - each notification by each channel but the
    feed, and what became of it;
  * `chime_preferences` - the settings people changed;
  * `chime_counts` - each person's counts of unseen and unread.

`up/1` takes `:version` and `:prefix` (the schema of the tables, in
PostgreSQL); `down/1` takes `:to` and `:prefix`.

# `check`

`:ok`, `{:pending, message}` or `{:outdated, message}`. Takes `:repo` and `:prefix`.

# `down`

Rolls the library's tables back to `:to` (default `0`). Call it from a host migration.

# `latest_version`

The latest version of the library's schema.

# `migrated_version`

The version the database is at (`0` when not installed).

# `run_backfills`

Runs deferred backfills to completion. Takes `:repo` and `:prefix`.

# `status`

The version, compatibility and backfills of a database. Takes `:repo` and `:prefix`.

# `up`

Migrates the library's tables up. Call it from a host migration.

# `verify`

Checks the tables against the library's schema. Takes `:repo` and `:prefix`.

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*Consult [api-reference.md](api-reference.md) for complete listing*