FRONTEND_MVC/migrations/m230405_032449_comments.php

<?php

use yii\db\Migration;

/**
 * Class m230405_032449_comments
 */
class m230405_032449_comments extends Migration
{
    /**
     * {@inheritdoc}
     */
    public function safeUp()
    {
        $sql = "ALTER TABLE `comments` ADD `parent_id` INT UNSIGNED NULL DEFAULT NULL AFTER `created_at`, ADD `likeed` INT NOT NULL DEFAULT '0' AFTER `parent_id`, ADD `fakename` VARCHAR(64) NULL DEFAULT NULL AFTER `likeed`, ADD INDEX `parent` (`parent_id`); COMMIT;";
        $this->execute($sql);
    }

    /**
     * {@inheritdoc}
     */
    public function safeDown()
    {
        echo "m230405_032449_comments cannot be reverted.\n";

        return false;
    }

    /*
    // Use up()/down() to run migration code without a transaction.
    public function up()
    {

    }

    public function down()
    {
        echo "m230405_032449_comments cannot be reverted.\n";

        return false;
    }
    */
}