class DatabaseTestBase

abstract class DatabaseTestBase extends KernelTestBase {
  use DatabaseTestSchemaDataTrait;
  use DatabaseTestSchemaInstallTrait;
  protected static $modules = [
    'database_test',
  ];
  
  /**
   * The database connection for testing.
   *
   * @var \Drupal\Core\Database\Connection
   */
  protected $connection;
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() {
    parent::setUp();
    $this->connection = Database::getConnection();
    $this->installSampleSchema();
    $this->addSampleData();
  }
  
  /**
   * Sets up tables for NULL handling.
   */
  public function ensureSampleDataNull() {
    $this->connection
      ->insert('test_null')
      ->fields([
      'name',
      'age',
    ])
      ->values([
      'name' => 'Kermit',
      'age' => 25,
    ])
      ->values([
      'name' => 'Fozzie',
      'age' => NULL,
    ])
      ->values([
      'name' => 'Gonzo',
      'age' => 27,
    ])
      ->execute();
  }

}