Fetch multi-row, single-column array using Doctrine - php

Question

I have a Doctrine fetch statement like this
$query = "SELECT id FROM table LIMIT 2";
$result = $db->fetchAll($query);
which returns the array like this:
Array
(
[0] => Array
(
[id] => 1
)
[1] => Array
(
[id] => 2
)
)
Since the only column I fetch is ID, I don't need the array scope do be that deep. Is there a convenient way of making Doctrine return the results in a "flat" array, similar to what what PDO does:
$result = $db->query($query)->fetchAll(PDO::FETCH_COLUMN);
will return
Array
(
[0] => 1
[1] => 2
)
Currently I am flattening it using
$result = call_user_func_array('array_merge', array_map("array_values", $result));

Answer 1

You can simply use the PDO functionality (at least if you have MySQL).
$ids = $db
->executeQuery($query)
->fetchAll(\PDO::FETCH_COLUMN)
;

Answer 2

To resolve this problem you have to make your custom doctrine hydrator.
First: Make your own hydrator
<?php
namespace MyProject\Hydrators;
use Doctrine\ORM\Internal\Hydration\AbstractHydrator;
class CustomHydrator extends AbstractHydrator
{
protected function _hydrateAll()
{
return $this->_stmt->fetchAll(PDO::FETCH_COLUMN);
}
}
Add your hydrator to Doctrine configuration file :
<?php
$em->getConfiguration()->addCustomHydrationMode('CustomHydrator','MyProject\Hydrators\CustomHydrator');
Finaly you can use your cutom hidrator :
<?php
$query = $em->createQuery('SELECT u FROM CmsUser u');
$results = $query->getResult('CustomHydrator');

Answer 3

I found a method called fetchFirstColumn which appears to do this. This was probably added in a later version of doctrine. I am currently on Doctrine ORM 2.7.4.
I am using it like this in Symfony:
$statement = $connection->prepare('SELECT foo FROM bar WHERE baz = :baz');
$statement->execute([':baz' => 1]);
$result = $statement->fetchFirstColumn();
The value of $result will be a numerically indexed array starting at 0 like this:
[
0 => 'foo1',
1 => 'foo2'
];

Answer 4

Fetch the data using fetchAssoc:
$result = $db->query($query)->fetchAssoc(PDO::FETCH_COLUMN);
You will get an Array like this:
Array (
[id] => 11
)