// Created on savesnippets.com · https://savesnippets.com/WV5nrbcFNM5Zu0
<?php
function whereIn(array $values): array {
    if (!$values) return ['(NULL)', []];   // SQL "IN ()" is a syntax error
    $placeholders = implode(',', array_fill(0, count($values), '?'));
    return ['(' . $placeholders . ')', array_values($values)];
}

[$inSql, $params] = whereIn([5, 12, 19, 22]);
$stmt = $db->prepare("SELECT * FROM users WHERE id IN $inSql");
$stmt->execute($params);
print_r($stmt->fetchAll());