My previous article "How to connect MySQL database using MySQLi procedural function" demonstrates the use of MySQLi procedural function mysqli_connect() is used to connect with a MySQL database and MySQLi extension also provides an Object Oriented interface for connecting to database.

MySQLi Object Oriented Style     

To open a connection to MySQL database using MySQLi Object Oriented style we use constructor of mysqli class (mysqli::__construct) which is an alias of mysqli_connect(). On successful connection, it returns an object which represents the connection.

Note : It also returned an object on Failure also (With Object Oriented style). To check the failure of connection we can use either $con->connect_error or mysqli_connect_error().

Syntax : mysqli::__construct(host_name, username, password, db_name, port, socket)

class mysqli {
 __construct ($host_name, $username, $password, $db_name, $port, $socket)
}
$con = new mysqli($host_name, $username, $password, $db_name, $port, $socket);

Parameters Description :

host_name : Specifies a host name or an IP address of MySQL server.

username : Specifies the MySQL username

password : Specifies the MySQL password

db_name : Specifies the default database to be used

port : Specifies the port number to connect to the MySQL server

socket : Specifies the socket name or named pipe

Example :

<?php
$host_name = "localhost";
$username = "username";
$password = "password";
$database = "test";//database name

// Create connection
$con = new mysqli($host_name, $username, $password, $database);

// Check connection
if (!$con) {
  echo "Error: " . $con->connect_error; die;
}
echo "Connection to database : ".$database." created successfully on server : ".$con->host_info;
?>