code: public function truncate()
  	{
  		$adapter = $this->dbAdapter;
  
  		$mapper = new \CronHelper\Model\JobMapper($adapter);
  		$where = new \Zend\Db\Sql\Where();
  
  		$mapper->deleteByWhere($where);
  	}
docs: Truncate database table.
  
  @return void