Migrations

• Enabling migrations
• Creating migrations
• Running migrations
• Rolling back migrations

Database migrations offer a convenient way to alter your databases in a structured and organized manner. They allow you to commit and roll back schema changes.

Mako migrations are created and executed from the reactor CLI tool.

Enabling migrations

You need to add a table called mako_migrations to your database. The table will be used to keep track of the migrations that have been ran. Here's the SQL for creating the table using MySQL:

CREATE TABLE `mako_migrations`
(
	`batch` int(10) unsigned NOT NULL,
	`package` varchar(255) NOT NULL,
	`version` varchar(255) NOT NULL
);

Creating migrations

Creating a migration is done from the reactor CLI tool:

php reactor migrate.create        // Creates an application migration
php reactor migrate.create foobar // Creates a migration for the "foobar" package

Running the create commands will return the following messages:

Migration created at "/var/www/app/migrations/20120824100019.php".
Migration created at "/var/www/app/packages/foobar/migrations/20120824100317.php".

The generated migration will contain a skeleton class with two methods, up and down.

class Migration_20120824100019
{
        /**
        * Makes changes to the database structure.
        *
        * @access  public
        */

        public function up()
        {

        }

        /**
        * Reverts the database changes.
        *
        * @access  public
        */

        public function down()
        {

        }
}

Running migrations

You can check if there are any outstanding migrations using the status command:

php reactor migrate.status

If there are outstanding migrations then you can run them like this:

php reactor migrate.up

This will show you the names of the migrations that were executed:

Ran the 20120824100019 migration.
Ran the foobar::20120824100317 migration.

Rolling back migrations

If you need to revert the changes made to your database then you can use the down command. This will roll back the last batch of migrations executed.

php reactor migrate.down

This will show you the migrations that were rolled back:

Rolled back the foobar::20120824100317 migration.
Rolled back the 20120824100019 migration.

You can roll back multiple batches by telling the rollback command how many batches you want to roll back.

php reactor migrate.down 2

If you want to roll back all database changes in one go then you can use the reset command.

php reactor migrate.reset

This will prompt you for confirmation. To force the reset just use the force option.

php reactor migrate.reset --force