$types = array();
while($field = mysql_fetch_field($result)){

    $types[$field->name] = $field->type;

    switch($field->type) {
         case "int":
                $types[$field->name] = 'int';
                break;
         case "real":
            $types[$field->name] = 'float';
            break;
        default:
            $types[$field->name] = 'string';
            break;
    }
}