Пример файла миграции Yii

m141202_180046_icon_created.php

<?php

class m141202_180046_icon_created extends CDbMigration
{
	// установка обновления
	public function up()
	{
		$this->addColumn('icons_by_name_view', 'created', 'datetime NOT NULL');
		$this->addColumn('similar_view', 'created', 'datetime NOT NULL');
		$this->refreshTableSchema('icons_by_name_view');
		$this->refreshTableSchema('similar_view');
	}

	// отмена обновления
	public function down()
	{
		$this->dropColumn('icons_by_name_view', 'created');
		$this->dropColumn('similar_view', 'created');
		$this->refreshTableSchema('icons_by_name_view');
		$this->refreshTableSchema('similar_view');
		return true;
	}
}