3.4 Object-Oriented Interface

The mysqli extension also allows you to manipulate the data using an object-oriented interface. Everything that can be done using the procedural interface is available this way. Here is the same sample transaction from the last section translated into the OO style:

$mysqli = new mysqli('db.example.org', 'web', 'xyz@123');

$mysqli->select_db('users');



$result = $mysqli->query("SELECT username FROM users");



while ($row = $result->fetch_assoc( )) {

    print $row['username'] . "\n";

}



$result->close( );

With the OO interface, there's no need to pass database handles as the first parameter to a mysqli method. Instead, the extension stores that handle as part of the mysqli object.

If you're porting code from mysql and use the default link option, you may find it easier to switch to the OO syntax because it doesn't require you to modify the argument list of every mysql function.

You can also use mysqli_init( ) and mysqli_real_connect( ):

$mysqli = new mysqli( );

$mysqli->init( );

$mysqli->options(MYSQLI_OPT_CONNECT_TIMEOUT, 120);

$mysqli->options(MYSQLI_OPT_LOCAL_INFILE, false);



$mysqli->real_connect('db.example.com', 'web', 'xyz@123', 'users', 

                       3306, NULL, MYSQLI_CLIENT_COMPRESS);

A new mysqli object does not automatically call mysqli_init( ) in its constructor. This is still your responsibility.

Certain mysqli functions are object properties instead of methods, in particular, mysqli_error( ), mysqli_errno( ), and mysqli_insert_id( ). Here's an example using mysqli_insert_id( ):

// place new e-mail address on list:

$email = 'rasmus@php.net';

$list  = 'php-general';



// escape data

$email = $mysqli->real_escape_string($email);

$list =  $mysqli->real_escape_string($list);



$mysqli = new mysqli($server, $user, $password);

$mysqli->query("INSERT INTO addresses VALUES(NULL, '$email')");

$id = $mysqli->insert_id; // no ( ) necessary!

$mysqli->query("INSERT INTO lists VALUES($id, '$list')");

A complete list of MySQLi classes, methods, and properties can be found at http://www.php.net/mysqli.