php__symfony__book/src/Migrations/MigrationBase.php

<?php

namespace App\Migrations;

use Doctrine\DBAL\Migrations\AbstractMigration;
use Doctrine\DBAL\Schema\Schema;

abstract class MigrationBase extends AbstractMigration {
  protected function ensureMySQL(): void {
    // this up() migration is auto-generated, please modify it to your needs
    $this->abortIf($this->connection->getDatabasePlatform()
        ->getName() !== 'mysql',
      'Migration can only be executed safely on \'mysql\'.');
  }

  public function down(Schema $schema) {
    $this->ensureMySQL();
  }

  public function up(Schema $schema) {
    $this->ensureMySQL();
  }
}