Transform result rows into another format in Doctrine DBAL

Code
<?php

/* @var $connection Doctrine\DBAL\Connection */

// Regular usage with fetchAll()
$sql 'SELECT * FROM test WHERE id < ?';

$result $connection->executeQuery($sql, [4])
    ->
fetchAll();

dump($result);

// Using project() to give result a format
$function = function ($row) {
    return 
$row['id'].';'.$row['name'].';'.
        
$row['creation_date'];
};

$result $connection->project($sql, [4], $function);

dump($result);
Result
array:3 [
0 => array:3 [
"id" => "1"
"name" => "foo"
"creation_date" => "2014-07-20 11:37:29"
]
1 => array:3 [
"id" => "2"
"name" => "test"
"creation_date" => "2014-07-20 10:40:22"
]
2 => array:3 [
"id" => "3"
"name" => "bar"
"creation_date" => "2014-07-23 07:27:18"
]
]

array:3 [
0 => "1;foo;2014-07-20 11:37:29"
1 => "2;test;2014-07-20 10:40:22"
2 => "3;bar;2014-07-23 07:27:18"
]