public function getNullConversion()
{
switch ($this->getAttribute(PDO::ATTR_ORACLE_NULLS)) {
case PDO::NULL_NATURAL:
return TDbNullConversionMode::Preserved;
case PDO::NULL_EMPTY_STRING:
return TDbNullConversionMode::EmptyStringToNull;
case PDO::NULL_TO_STRING:
return TDbNullConversionMode::NullToEmptyString;
}
}