how to see if database exists with PDO [duplicate]

PHP Snippet 1:

$stmt = $pdo->query("SELECT COUNT(*) FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = 'DBName'");
return (bool) $stmt->fetchColumn();

PHP Snippet 2:

        try {
            $conn->exec($sql);
        } catch (PDOException $th) {
            echo "<br> sql error";
        }