I\'m using PDO to execute a statement with an IN clause that uses an array for its values:
$in_array = array(1, 2, 3);
$in_values = implode(\',\'
As PDO doesn't seem to provide a good solution, you might as well consider using DBAL, which mostly follows PDO's API, but also adds some useful features http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/data-retrieval-and-manipulation.html#list-of-parameters-conversion
$stmt = $conn->executeQuery('SELECT * FROM articles WHERE id IN (?)',
array(array(1, 2, 3, 4, 5, 6)),
array(\Doctrine\DBAL\Connection::PARAM_INT_ARRAY)
);
There are probably some other packages out there that don't add complexity and don't obscure the interaction with the database (like most ORM do), but at the same time make small typical tasks bit easier.