PDO_SQLITE is a driver that implements the PHP
Data Objects (PDO) interface to enable access to SQLite 3 databases.
In PHP 5.1, the SQLite extension also
provides a driver for SQLite 2 databases; while it is not technically a
part of the PDO_SQLITE driver, it behaves similarly, so it is
documented alongside it. The SQLite 2 driver for PDO is provided
primarily to make it easier to import legacy sqlite 2 database files into
an application that uses the faster, more efficient sqlite 3 driver. As
a result, the SQLite 2 driver is not as feature-rich as the SQLite 3
driver.