Oracle 5.0 Reference Manual page 2329

• Enhanced debugging capabilities
• Embedded server support
Note
If you are using MySQL versions 4.1.3 or later it is strongly recommended that
you use this extension.
As well as the object-oriented interface the extension also provides a procedural interface.
The extension is built using the PHP extension framework, its source code is located in the
mysqli
directory ext/mysqli.
For further information on the
(Mysqli)".
What is PDO?
PHP Data Objects, or PDO, is a database abstraction layer specifically for PHP applications. PDO
provides a consistent API for your PHP application regardless of the type of database server your
application will connect to. In theory, if you are using the PDO API, you could switch the database
server you used, from say Firebird to MySQL, and only need to make minor changes to your PHP
code.
Other examples of database abstraction layers include JDBC for Java applications and DBI for Perl.
While PDO has its advantages, such as a clean, simple, portable API, its main disadvantage is that it
doesn't allow you to use all of the advanced features that are available in the latest versions of MySQL
server. For example, PDO does not allow you to use MySQL's support for Multiple Statements.
PDO is implemented using the PHP extension framework, its source code is located in the directory
ext/pdo.
For further information on PDO, see the http://www.php.net/book.pdo.
What is the PDO MYSQL driver?
The PDO MYSQL driver is not an API as such, at least from the PHP programmer's perspective.
In fact the PDO MYSQL driver sits in the layer below PDO itself and provides MySQL-specific
functionality. The programmer still calls the PDO API, but PDO uses the PDO MYSQL driver to carry
out communication with the MySQL server.
The PDO MYSQL driver is one of several available PDO drivers. Other PDO drivers available include
those for the Firebird and PostgreSQL database servers.
The PDO MYSQL driver is implemented using the PHP extension framework. Its source code is
located in the directory ext/pdo_mysql. It does not expose an API to the PHP programmer.
For further information on the PDO MYSQL driver, see
(PDO_MYSQL) (MySQL
What is PHP's MySQL Native Driver?
In order to communicate with the MySQL database server the
MYSQL driver each use a low-level library that implements the required protocol. In the past, the only
available library was the MySQL Client Library, otherwise known as libmysqlclient.
However, the interface presented by
PHP applications, as
libmysqlclient
reason the MySQL Native Driver, mysqlnd, was developed as an alternative to
PHP applications.
MySQL Improved Extension (Mysqli)
extension, see
mysqli
(PDO))".
libmysqlclient
was originally designed with C applications in mind. For this
2309
Section 20.7.3, "MySQL Improved Extension
Section 20.7.4, "MySQL Functions
extension,
mysql
was not optimized for communication with
and the PDO
mysqli
for
libmysqlclient