PHP Manual: Opens a connection to a mysql server

Description

Object oriented style

bool mysqli::real_connect ([ string $host [, string $username [, string $passwd [, string $dbname [, int $port [, string $socket [, int $flags ]]]]]]] )

Procedural style

bool mysqli_real_connect ( mysqli $link [, string $host [, string $username [, string $passwd [, string $dbname [, int $port [, string $socket [, int $flags ]]]]]]] )

Establish a connection to a MySQL database engine.

This function differs from mysqli_connect:

mysqli_real_connect needs a valid object which has to be created by function mysqli_init.
With the mysqli_options function you can set various options for connection.
There is a flags parameter.

Parameters

link

Procedural style only: A link identifier returned by mysqli_connect or mysqli_init

host

Can be either a host name or an IP address. Passing the NULL value or the string "localhost" to this parameter, the local host is assumed. When possible, pipes will be used instead of the TCP/IP protocol.

username

The MySQL user name.

passwd

If provided or NULL, the MySQL server will attempt to authenticate the user against those user records which have no password only. This allows one username to be used with different permissions (depending on if a password as provided or not).

dbname

If provided will specify the default database to be used when performing queries.

port

Specifies the port number to attempt to connect to the MySQL server.

socket

Specifies the socket or named pipe that should be used.

Note:
Specifying the socket parameter will not explicitly determine the type of connection to be used when connecting to the MySQL server. How the connection is made to the MySQL database is determined by the host parameter.

flags

With the parameter flags you can set different connection options:

**Supported flags**
Name	Description
`MYSQLI_CLIENT_COMPRESS`	Use compression protocol
`MYSQLI_CLIENT_FOUND_ROWS`	return number of matched rows, not the number of affected rows
`MYSQLI_CLIENT_IGNORE_SPACE`	Allow spaces after function names. Makes all function names reserved words.
`MYSQLI_CLIENT_INTERACTIVE`	Allow interactive_timeout seconds (instead of wait_timeout seconds) of inactivity before closing the connection
`MYSQLI_CLIENT_SSL`	Use SSL (encryption)
`MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT`	Like `MYSQLI_CLIENT_SSL`, but disables validation of the provided SSL certificate. This is only for installations using MySQL Native Driver and MySQL 5.6 or later.

Note:
For security reasons the MULTI_STATEMENT flag is not supported in PHP. If you want to execute multiple queries use the mysqli_multi_query function.

Changelog

Version	Description
5.6.16	Added the `MYSQLI_CLIENT_SSL_DONT_VERIFY_SERVER_CERT` flag for MySQL Native Driver

Return Values

Returns TRUE on success or FALSE on failure.

Examples

Example #1 mysqli::real_connect example

Object oriented style


<?php

$mysqli = mysqli_init();
if (!$mysqli) {
    die('mysqli_init failed');
}

if (!$mysqli->options(MYSQLI_INIT_COMMAND, 'SET AUTOCOMMIT = 0')) {
    die('Setting MYSQLI_INIT_COMMAND failed');
}

if (!$mysqli->options(MYSQLI_OPT_CONNECT_TIMEOUT, 5)) {
    die('Setting MYSQLI_OPT_CONNECT_TIMEOUT failed');
}

if (!$mysqli->real_connect('localhost', 'my_user', 'my_password', 'my_db')) {
    die('Connect Error (' . mysqli_connect_errno() . ') '
            . mysqli_connect_error());
}

echo 'Success... ' . $mysqli->host_info . "\n";

$mysqli->close();
?>

Object oriented style when extending mysqli class


<?php

class foo_mysqli extends mysqli {
    public function __construct($host, $user, $pass, $db) {
        parent::init();

        if (!parent::options(MYSQLI_INIT_COMMAND, 'SET AUTOCOMMIT = 0')) {
            die('Setting MYSQLI_INIT_COMMAND failed');
        }

        if (!parent::options(MYSQLI_OPT_CONNECT_TIMEOUT, 5)) {
            die('Setting MYSQLI_OPT_CONNECT_TIMEOUT failed');
        }

        if (!parent::real_connect($host, $user, $pass, $db)) {
            die('Connect Error (' . mysqli_connect_errno() . ') '
                    . mysqli_connect_error());
        }
    }
}

$db = new foo_mysqli('localhost', 'my_user', 'my_password', 'my_db');

echo 'Success... ' . $db->host_info . "\n";

$db->close();
?>

Procedural style


<?php

$link = mysqli_init();
if (!$link) {
    die('mysqli_init failed');
}

if (!mysqli_options($link, MYSQLI_INIT_COMMAND, 'SET AUTOCOMMIT = 0')) {
    die('Setting MYSQLI_INIT_COMMAND failed');
}

if (!mysqli_options($link, MYSQLI_OPT_CONNECT_TIMEOUT, 5)) {
    die('Setting MYSQLI_OPT_CONNECT_TIMEOUT failed');
}

if (!mysqli_real_connect($link, 'localhost', 'my_user', 'my_password', 'my_db')) {
    die('Connect Error (' . mysqli_connect_errno() . ') '
            . mysqli_connect_error());
}

echo 'Success... ' . mysqli_get_host_info($link) . "\n";

mysqli_close($link);
?>

The above examples will output:

Success... MySQL host info: localhost via TCP/IP

Notes

Note:
MySQLnd always assumes the server default charset. This charset is sent during connection hand-shake/authentication, which mysqlnd will use.
Libmysqlclient uses the default charset set in the my.cnf or by an explicit call to mysqli_options prior to calling mysqli_real_connect, but after mysqli_init.

mysqli::real_connect

mysqli_real_connect