How to get a one-dimensional scalar array as a doctrine dql query result?

Question

I want to get an array of values from the id column of the Auction table. If this was a raw SQL I would write:

SELECT id FROM auction

But w

Answer 1

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