PDO (PHP Data Objects)

Publisher : Anuj Kumar

Course Length : 31 mins

Course Language : English

Description

PDO (PHP Data Objects) is a PHP extension through which we can access and work with databases. Though PDO is similar in many aspects to mySQLi, it is better to work with for the following reasons:

•  It is better protected against hackers.
• It is consistent across databases, so it can work with MySQL as well as other types of databases (SQLite, Oracle, PostgreSQL, etc.)
•  It is object oriented at its core.

PDO Support 12 diffrent database drivers.

Driver name	Supported databases
PDO_CUBRID	Cubrid
PDO_DBLIB	FreeTDS / Microsoft SQL Server / Sybase
PDO_FIREBIRD	Firebird
PDO_IBM	IBM DB2
PDO_INFORMIX	IBM Informix Dynamic Server
PDO_MYSQL	MySQL 3.x/4.x/5.x
PDO_OCI	Oracle Call Interface
PDO_ODBC	ODBC v3 (IBM DB2, unixODBC and win32 ODBC)
PDO_PGSQL	PostgreSQL
PDO_SQLITE	SQLite 3 and SQLite 2
PDO_SQLSRV	Microsoft SQL Server / SQL Azure
PDO_4D	4D

All of these drivers are not necessarily available on your system , you can find list ob available in your system by using this command 

print_r(PDO::getAvailableDrivers()); 

In this PDO  tutorial you will find recipes for 4 basic functions that we perform with the database: insertion, selection, update, and deletion. The recipes are intended to work with MySQL, but we can easily switch it with another database.

How to connect with the database through PDO?

It is considered good practice to wrap the database connection within a try-catch block so that, if anything goes wrong, an exception will be thrown. We can customize the error message but, in order to keep things simple, we’ll settle with the error message that PDO provides.

In order to connect to the database, we’ll need the database name, username, and password.

// DB credentials.
define('DB_HOST','localhost');
define('DB_USER','your user name');
define('DB_PASS','your user password');
define('DB_NAME','your database name');
// Establish database connection.
try
{
$dbh = new PDO("mysql:host=".DB_HOST.";dbname=".DB_NAME,
DB_USER, DB_PASS,
array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'"));
}
catch (PDOException $e)
{
exit("Error: " . $e->getMessage());
}

How to close the database connection?

PHP automatically closes the database connection but, if the need arises, we can deliberately close the connection with the following line of code:

$dbh = null;