private function prepareColumnValues($tableName, $row)
    {
        $ret = array();
        $columnTypes = $this->tableColumnTypes[$tableName];
        foreach ($row as $colName => $colValue) {
            $colValue = $this->hookTransformColumnValue($tableName, $colName, $colValue, $row);
            $ret[] = $this->escape($colValue, $columnTypes[$colName]);
        }

        return $ret;
    }