PDO using PDO::FETCH_PROPS_LATE and __construct() call?

I'm trying to create a new instance of Setting object calling __construct() method with PHP PDO and constrain PDO::FETCH_PROPS_LATE. Unfortunatly i'm getting this warning (and binding doesn't work).

How can pass column values to the constructor method?

Warning: Missing argument 1 for Setting::__construct() in pdo.php.

Notice: Undefined variable: key in pdo.php.

class Setting
{

    protected $key, $value, $displayable;

    public function __construct($key, $value = null, $displayable = 1)
    {
        $this->key         = $key;
        $this->value       = $value;
        $this->displayable = $displayable > 0;
    }

}

while($mashup = current($mashups))
{
    $stmt = $dbh->prepare('SELECT `key`, value, displayable
        FROM setting WHERE mashup_id = :id');

    $stmt->bindParam(':id', $mashup->id, PDO::PARAM_INT);
    $stmt->execute();

    $settings = $stmt->fetchAll(PDO::FETCH_CLASS|PDO::FETCH_PROPS_LATE,
       'Setting');
}

$stmt->closeCursor();

Solution

The constructor specifies $key parameter as mandatory, because it has no default value provided:

public function __construct(
    $key // <---no default value
    $value = null,
    $displayable = 1
)

So, when you are doing this:

$settings = $stmt->fetchAll(PDO::FETCH_CLASS|PDO::FETCH_PROPS_LATE, 'Setting');

you get warning: Missing argument 1 for Setting::__construct() in pdo.php.
The error is thrown only for parameter $key because this has no default value and you aren't providing any.

The correct use of fetchAll is by providing the optional parameter $constructorArgs (see available signatures):

$rows = $stmt->fetchAll(PDO::FETCH_CLASS|PDO::FETCH_PROPS_LATE,
    'classname', 
    <array of arguments, with same order used in constructor>
);

So, in your case:

$rows = $stmt->fetchAll(PDO::FETCH_CLASS|PDO::FETCH_PROPS_LATE,
    'Setting', 
    array('your-value-for-key-parameter') // nullable params can be omitted or partially specified, same as for any php function/method
);