//Fetch the value of count, and then increment it

$username="aaa";
$password="bbb";
$database="ccc";
$count = 0;
try {
    $dbh = new PDO('mysql:host=localhost;dbname='.$database, $username, $password);
    foreach($dbh->query('SELECT count from t_count') as $row) {
        $count = $row['count'];
        print $count;
    }
    $sql = "update t_count set count=:count";
	$q = $dbh->prepare($sql);
	$q->execute(array(':count'=>$count+1));
	 
    $dbh = null;
} catch (PDOException $e) {
    print "Error!: " . $e->getMessage() . "
";
    die();
}