Here we are solving a basic problem faced by a beginner web developer in PHP i.e. Connect to MySQL database using PDO.

PDO Installation

For installation details, go to:

Open a Connection to MySQL

$dsn = "mysql:dbname=testdb;host=";
$un = "dbuser";
$ps = "dbpass";
    $dbh = new PDO($dsn, $un, $ps);
catch (PDOException $e) 
    echo "Connection failed: " . $e->getMessage();

Close the Connection

The connection will be closed automatically when the script ends. To close the connection before, use the following:

$dbh = null;

Should I Use MySQLi or PDO?

If you need a short answer, it would be "Whatever you like". Both MySQLi and PDO have their advantages: PDO will work on 12 different database systems, where as MySQLi will only work with MySQL databases. So, if you have to switch your project to use another database, PDO makes the process easy. You only have to change the connection string and a few queries. With MySQLi, you will need to rewrite the entire code - queries included. Both are object-oriented, but MySQLi also offers a procedural API. Both support Prepared Statements. Prepared Statements protect from SQL injection, and are very important for web application security.