/**
* Find records by using a sql statement, avoid to use this method if you
* can do it in another way (like using default find methods)
*
* @param $sql SQL Statement
* @return array Array of objects returned by query
*/
public function find_by_sql($sql)
{
$data = DbCommand::all($sql);
$data = array_map(array($this, 'map_object'), $data);
foreach ($data as $model) {
$model->_exists = true;
}
return $data;
}