Database Query Function (Users Online)

    //Query looks at table for users with Yes in the logged_in column
    //which means they are logged in and gives the usernames.

    require("connect/connect.php");

    //Function to get all usernames that are online
    function usersOnline($pdo){
        $online = 'Yes';

        $query = ("SELECT username FROM users WHERE logged_in = ?");

        $stmt1 = $pdo->prepare($query);

        $stmt1->bindParam(1,$online);
        $stmt1->execute();

        $rows = $stmt1->fetchAll(PDO::FETCH_ASSOC);

        foreach($rows as $val){echo "{$val['username']}". " ";}
    }

//To call the function - <?php usersOnline($pdo); ?>