PDO and the PDO_SQLITE driver is enabled by default. You may need to enable the PDO driver for your database of choice; consult the documentation for database-specific PDO drivers to find out more about that.

Note:

When building PDO as a shared extension (not recommended) then all PDO drivers must be loaded after PDO itself.

When installing PDO as a shared module, the php.ini file needs to be updated so that the PDO extension will be loaded automatically when PHP runs. You will also need to enable any database specific drivers there too; make sure that they are listed after the extension=pdo line, as PDO must be initialized before the database-specific extensions can be loaded. If you built PDO and the database-specific extensions statically, you can skip this step.

extension=pdo

PDO is enabled by default. Choose the other database-specific DLL files and either use dl to load them at runtime, or enable them in php.ini. For example, this loads the PDO_SQLITE driver but leaves the PDO_ODBC driver commented out:

;extension=pdo_odbc
extension=pdo_sqlite

These DLLs should exist in the system's extension_dir.