How to get a one-dimensional scalar array as a doctrine dql query result?
A better solution is to use PDO:FETCH_COLUMN
. To do so you need a custom hydrator:
//MyProject/Hydrators/ColumnHydrator.php
namespace DoctrineExtensions\Hydrators\Mysql;
use Doctrine\ORM\Internal\Hydration\AbstractHydrator, PDO;
class ColumnHydrator extends AbstractHydrator
{
protected function hydrateAllData()
{
return $this->_stmt->fetchAll(PDO::FETCH_COLUMN);
}
}
Add it to Doctrine:
$em->getConfiguration()->addCustomHydrationMode('COLUMN_HYDRATOR', 'MyProject\Hydrators\ColumnHydrator');
And you can use it like this:
$em->createQuery("SELECT a.id FROM Auction a")->getResult("COLUMN_HYDRATOR");
More info: http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/dql-doctrine-query-language.html#custom-hydration-modes
PHP < 5.5
You can use array_map
, and since you only have on item per array, you can elegantly use
'current'
as callback, instead of writing a closure.
$result = $em->createQuery("SELECT a.id FROM Auction a")->getScalarResult();
$ids = array_map('current', $result);
See Petr Sobotka's answer below for additional info regarding memory usage.
PHP >= 5.5
As jcbwlkr's answered below, the recommended way it to use array_column
.
As of PHP 5.5 you can use array_column to solve this
$result = $em->createQuery("SELECT a.id FROM Auction a")->getScalarResult();
$ids = array_column($result, "id");
Ascarius' answer is elegant, but beware of memory usage! array_map()
creates a copy of passed array and effectively doubles memory usage. If you work with hundreds of thousands of array items this can become an issue. Since PHP 5.4 call-time pass by reference has been removed so you cannot do
// note the ampersand
$ids = array_map('current', &$result);
In that case you can go with obvious
$ids = array();
foreach($result as $item) {
$ids[] = $item['id'];
}