Removed rows from a 2d array if a column value has been encountered more than once

How can I check if the values are unique in an array based on the key value?

Below is the output of the array. I want to remove duplicate values based on the "id" key. If you check below, the 2nd & 3rd array are same except for the "role" value. Because of this, array_unique is not working on this array.

[
    [
        'id' => '1521422',
        'name' => 'David Alvarado',
        'role' => 'associate producer  ',
    ],
    [
        'id' => '0098210',
        'name' => 'Cristian Bostanescu',
        'role' => 'line producer: Romania  (as Cristi Bostanescu)',
    ],
    [
        'id' => '1266015',
        'name' => 'Bruno Hoefler',
        'role' => 'co-producer  ',
    ],
    [
        'id' => '1266015',
        'name' => 'Bruno Hoefler',
        'role' => 'executive producer  ',
    ],
    [
        'id' => '1672379',
        'name' => 'Alwyn Kushner',
        'role' => 'associate producer  ',
    ],
]

Try this one:

<?php
$array = array(
    array('id' => 1, 'text' => 'a'),
    array('id' => 2, 'text' => 'b'),
    array('id' => 1, 'text' => 'c'),
    array('id' => 3, 'text' => 'd')
);
$array = array_filter($array, function ($item) {
    static $found = array();
    if (isset($found[$item['id']])) return false;
    $found[$item['id']] = true;
    return true;
});

var_dump($array);

This works as of PHP 5.3 (because of the closure and static statement).

cf. http://php.net/manual/en/function.array-filter.php for more information. I tested the statement within loops, it works there as well.