I used PDO for somewhere, right now extract its document
for a short summary:
1. 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.
2. 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. The following is an example of prepared statements.
$stmt = $dbh->prepare("INSERT INTO REGISTRY (name, value) VALUES (:name, :value)");
// insert one row
$name = 'one';
$value = 1;
// insert another row with different values
$name = 'two';
$value = 2;