Не выбирает базу данных

Момент создания базы

<?php
include 'db.php';

$stmt = $pdo->prepare("
    CREATE DATABASE playground
");
$stmt ->execute();

Момент выбора базы

<?php
include 'db.php';

$stmt = $pdo->prepare("
    USE playground
");
$stmt ->execute();

Ошибка:

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOStatement::fetchAll(). Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.