Can I create a database using PDO in PHP?

Yes, you can.

The dsn part, which is the first parameter of the PDO constructor, does not have to have a database name. You can simply use mysql:host=localhost. Then, given you have the right privilege, you can use regular SQL commands to create a database and users, etc.

Following is an example from an install.php file. It logs in with root, create a database, a user, and grant the user all privilege to the new created database:

<?php

    $host = "localhost";

    $root = "root";
    $root_password = "rootpass";

    $user = 'newuser';
    $pass = 'newpass';
    $db = "newdb";

    try {
        $dbh = new PDO("mysql:host=$host", $root, $root_password);

        $dbh->exec("CREATE DATABASE `$db`;
                CREATE USER '$user'@'localhost' IDENTIFIED BY '$pass';
                GRANT ALL ON `$db`.* TO '$user'@'localhost';
                FLUSH PRIVILEGES;")
        or die(print_r($dbh->errorInfo(), true));

    }
    catch (PDOException $e) {
        die("DB ERROR: " . $e->getMessage());
    }
?>