PHP & MySQL - Connect to MySQL

The MySQLi extension of PHP allows you to access MySQL database servers. It is designed to work with MySQL version 4.1 and above.

Installation & Runtime Configuration

The MySQLi extension was introduced with PHP version 5.0.0. The MySQL Native Driver was included in PHP version 5.3.0.

For installation details, go to: https://php.net/manual/en/mysqli.installation.php

For runtime configuration details, go to: https://php.net/manual/en/mysqli.configuration.php

mysqli_connect() function

To connect to the MySQL server, mysqli_connect() function can be used. The syntax for using this function is mentioned below:

//Object-oriented style
public mysqli::connect(hostname, username, password, 
                       database, port, socket)

//Procedural style
mysqli_connect(hostname, username, password, 
               database, port, socket)

Parameters

`hostname`	`Optional.` Specify the host name or an IP address. Passing the null value or "localhost" to this parameter, the local host is assumed.
`username`	`Optional.` Specify the MySQL user name.
`password`	`Optional.` Specify the MySQL password. This allows the username to be used with different permissions (depending on if a password is provided or not).
`database`	`Optional.` If provided will specify the default database to be used when performing queries.
`port`	`Optional.` Specify the port number to attempt to connect to the MySQL server.
`socket`	`Optional.` Specify the socket or named pipe that should be used.

Connect to MySQL Database - Object-oriented style

The example below demonstrates how to connect to the MySQL database using object-oriented style.

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDatabase";

//establishing connection 
$mysqli = new mysqli($servername, $username, $password, $dbname);

//checking connection
if ($mysqli->connect_errno) {
  echo "Failed to connect to MySQL: ". $mysqli->connect_error;
  exit();
}

echo "Connected successfully.";

//closing the connection
$mysqli->close();
?>

The output of the above code will be:

Connected successfully.

Connect to MySQL Database - Procedural style

The same can be achieved using procedural style with following script:

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDatabase";

//establishing connection 
$mysqli = mysqli_connect($servername, $username, $password, $dbname);

//checking connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: ". mysqli_connect_error();
  exit();
}

echo "Connected successfully.";

//closing the connection
mysqli_close($mysqli);
?>

The output of the above code will be:

Connected successfully.

Complete PHP MySQLi Reference

For a complete reference of all properties, methods and functions of PHP MySQLi extension, see PHP MySQLi Reference.