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();
    }

}