# PHP Data Objects

&reftitle.intro;

The `PHP Data Objects` (PDO) extension defines a lightweight, consistent interface for accessing databases in PHP. Each database driver that implements the PDO interface can expose database-specific features as regular extension functions. Note that you cannot perform any database functions using the PDO extension by itself; you must use a database-specific PDO driver to access a database server.

PDO provides a data-access abstraction layer, which means that, regardless of which database you're using, you use the same functions to issue queries and fetch data. PDO does not provide a database abstraction; it doesn't rewrite SQL or emulate missing features. You should use a full-blown abstraction layer if you need that facility.

PDO ships with PHP.

&reference.pdo.setup; &reference.pdo.constants; &reference.pdo.connections; &reference.pdo.transactions; &reference.pdo.prepared-statements; &reference.pdo.error-handling; &reference.pdo.lobs; &reference.pdo.pdo; &reference.pdo.pdostatement; &reference.pdo.pdorow; &reference.pdo.pdoexception; &reference.pdo.drivers;