code: public function all($db = null)
      {
          if ($this->emulateExecution) {
              return [];
          }
          $rows = $this->createCommand($db)->queryAll();
          return $this->populate($rows);
      }
docs: Executes the query and returns all results as an array.
  @param Connection $db the database connection used to generate the SQL statement.
  If this parameter is not given, the `db` application component will be used.
  @return array the query results. If the query results in nothing, an empty array will be returned.