Are PDO prepared statements sufficient to prevent SQL injection?

Let's say I have code like this: $dbh = new PDO("blahblah"); $stmt = $dbh->prepare('SELECT * FROM users where username = :username'); $stmt->execute( array(':username' => $_REQUEST['username']) ); The PDO documentation says: > The parameters to prepared statements don't need to be quoted; the driver handles it for you. **Is that truly all I need to do to avoid SQL injections? Is it really that easy?** You can assume MySQL if it makes a difference. Also, I'm really only curious about the use of prepared statements against SQL injection. In this context, I don't care about XSS or other possible vulnerabilities.