/**
  * Get the corresponding php type of a $sql_type type
  *
  * @return string
  */
 private function getPommType(Session $session, $sql_type)
 {
     $pomm_types = $session->getPoolerForType('converter')->getConverterHolder()->getTypesWithConverterName();
     if (!isset($pomm_types[$sql_type])) {
         throw new \RuntimeException("Invalid {$sql_type}");
     }
     return $pomm_types[$sql_type];
 }