use Drupal\Core\Extension\ModuleHandlerInterface;

/**
* The module handler service.
*/
protected ModuleHandlerInterface $moduleHandler;

/**
 * Constructs a form.
 *
 * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
 *   The module handler 

$connection = Database::getConnection();
$fields = $connection->query("DESCRIBE `my_table`")->fetchAll();
foreach ($fields as $field) {
 if ($field->Field === 'column_name') {
   // Do something.
 }
}

drush ev "echo \Drupal::service('update.update_hook_registry')->getInstalledVersion('my_module')"

if (\Drupal::database()->schema()->tableExists('my_table')) {
  // Do something.
}

drush si standard --locale en --site-name=Test --site-mail=noreply@example.com --account-name=admin --account-pass=123 -y

drush sqlq --extra='-ss' "show tables like 'migrate_%'" | sed -r '/^\s*$/d' | while read TABLE ; do echo "drush sqlq 'DROP TABLE $TABLE;'" ; done

/**
 * {@inheritdoc}
 */
public function buildForm(array $form, FormStateInterface $form_state) {
 $form['#attached'] = [
   'library' => ['my_module/my_library'],
 ];
 return $form;
}

use Drupal\file\FileUsage\DatabaseFileUsageBackend;

 /**
 * File usage service.
 */
protected DatabaseFileUsageBackend $fileUsage;

/**
 * Constructs an object.
 *
 * @param \Drupal\file\FileUsage\DatabaseFileUsageBackend $file_usage
 *   File usage service.
 */

use Drupal\Core\Queue\QueueInterface;

/**
* The queue object for a given name.
*/
protected QueueInterface $queue;

/**
 * Constructs an object.
 *
 * @param \Drupal\Core\Queue\QueueInterface $queue
 *   The queue object for a given name.
 */

use Drupal\Core\Database\Connection;

/**
 * The database connection.
 */
protected Connection $database;
 
/**
 * Constructs an object.
 *
 * @param \Drupal\Core\Database\Connection $database
 *   The database connection.
 */
public