PHP Data Objects is a great and easy-to-use technology. However, it's still in its infancy and many improvements and other changes are yet to come. Be sure to keep yourself updated with the latest news from PHP developers and from the large community of PHP fans and users.
Effective use of PDO and PHP in general, is possible only with a sound understanding of security threats and how to protect against them. Using PDO's prepared statements diminishes the risk of SQL injection attacks, but you, the developer, are still responsible for securing your application. Make sure that you keep track of the latest developments in the security field.
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