=pod

=encoding utf8
 
=head1 NAME
 
Mojolicious::Command::migration — MySQL migration tool for Mojolicious

=head1 VERSION

version 0.12

=head1 SYNOPSIS
 
  Usage: APPLICATION migration [COMMAND] [OPTIONS]
 
    mojo migration prepare
  
  Commands:
    status     : Current database and schema version
    install    : Install a version to the database.
    prepare    : Makes deployment files for your database
    upgrade    : Upgrade the database.
    downgrade  : Downgrade the database.
 
=head1 DESCRIPTION
 
L<Mojolicious::Command::migration> MySQL migration tool.
 

=head1 USAGE

L<Mojolicious::Command::migration> uses app->db for mysql connection and following configuration:

  {
    'user'       => 'USER',
    'password'   => 'PASSWORD',
    'datasource' => { 'database' => 'DB_NAME'},
  }

from

  $ app->config->{db}->{mysql}

All deploy files saves to relative directory 'share/'. You can change it with 'MOJO_MIGRATION_SHARE' environment.
Current project state saves to 'tmp/.deploy_status' file. You can change directory with 'MOJO_MIGRATION_TMP' environment.

Note: we create directories automatically

=head1 COMMANDS
 
=head2 status
 
  $ app migration status
  Schema version: 21
  Deployed database is 20

Returns the state of the deployed database (if it is deployed) and the state of the current schema version. Sends this as a string to STDOUT

=head2 prepare

Makes deployment files for the current schema. If deployment files exist, will fail unless you "overwrite_migrations".

  # have changes
  $ app migration prepare
  Schema version: 21
  New version is 22
  Deploy to 22
  
  # no changes
  $ app migration prepare
  Schema version: 21
  Nothing to upgrade. Exit

=head2 install

Installs either the current schema version (if already prepared) or the target version specified via any to_version flags.

If you try to install to a database that has already been installed (not empty), you'll get an error. Use flag force to set current database to schema version without changes database.

  # last
  $ app migration install
  Schema version: 21
  Deploy database to 21
  
  # target version
  $ app migration install --to-version 10
  Schema version: 21
  Deploy database to 10

  # force install
  $ app migration install --force
  Schema version: 21
  Force deploy to 21

=head2 upgrade


Use flag --force to set current database to schema version without changes database.

  # last
  $ app migration upgrade
  Schema version: 21
  Database version: 20
  Upgrade to 21
  
  # target version
  $ app migration upgrade --to-version 10
  Schema version: 21
  Database version: 8
  Upgrade to 10

  # force upgrade
  $ app migration upgrade --force
  Schema version: 21
  Database version: 8
  Force upgrade to 21

=head2 downgrade


Use flag --force to set current database to schema version without changes database.

  # last
  $ app migration downgrade
  Schema version: 21
  Database version: 20
  Downgrade to 21
  
  # target version
  $ app migration downgrade --to-version 10
  Schema version: 21
  Database version: 8
  Downgrade to 10

  # force downgrade
  $ app migration downgrade --force
  Schema version: 21
  Database version: 8
  Force downgrade to 21

=head1 Custom upgrade and downgrade

You can customize upgrade and downgrade by adding additional SQL scripts to path of action. All scripts will be executed in alphabetical order.

  # share/migration/MySQL/upgrade/10-11/001_auto.sql is automatic
  # share/migration/MySQL/upgrade/10-11/002_some_script.sql is additional sctipt
  $ app migration upgrade
  Schema version: 11
  Database version: 10
  Upgrade to 11
  Exec file: share/migrations/MySQL/upgrade/10-11/001_auto.sql
  Exec file: share/migrations/MySQL/upgrade/10-11/002_some_script.sql

=head1 SOURCE REPOSITORY

L<https://github.com/likhatskiy/Mojolicious-Command-migration>

=head1 AUTHOR

Alexey Likhatskiy, <likhatskiy@gmail.com>

=head1 LICENSE AND COPYRIGHT

Copyright (C) 2015 "Alexey Likhatskiy"

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.