多字段去重php

$insert[] = [
    'where' => $sv2['cpy_empcode1'],
    'card_id' => $sv2['card_id'],
];

$container = array();
$result = array();
$number = 1;
foreach ($insert as $item) {
    $key = $item['where'] . '_' . $item['card_id'];
    if (empty($container[$key])) {
        $container[$key] = $number;
    } else {
        $container[$key] += $number;
    }
}
foreach ($container as $key => $item) {
    list($where, $card_id) = explode('_', $key);
    $result[] = array('where' => $where, 'card_id' => $card_id);

}