Prado\Data\TDbConnection::setNullConversion PHP Метод

    public function setNullConversion($value)
    {
        switch (TPropertyValue::ensureEnum($value, 'Prado\\Data\\TDbNullConversionMode')) {
            case TDbNullConversionMode::Preserved:
                $value = PDO::NULL_NATURAL;
                break;
            case TDbNullConversionMode::EmptyStringToNull:
                $value = PDO::NULL_EMPTY_STRING;
                break;
            case TDbNullConversionMode::NullToEmptyString:
                $value = PDO::NULL_TO_STRING;
                break;
        }
        $this->setAttribute(PDO::ATTR_ORACLE_NULLS, $value);
    }