PHP Manual: Opens a connection to a mysql server

Description

Object-oriented style

public bool mysqli::real_connect(
    stringnull $hostname = null,
    stringnull $username = null,
    #[\SensitiveParameter]stringnull $password = null,
    stringnull $database = null,
    intnull $port = null,
    stringnull $socket = null,
    int $flags = 0
)

Procedural style

bool mysqli_real_connect(
    mysqli $mysql,
    stringnull $hostname = null,
    stringnull $username = null,
    #[\SensitiveParameter]stringnull $password = null,
    stringnull $database = null,
    intnull $port = null,
    stringnull $socket = null,
    int $flags = 0
)

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

mysql

Procedural style only: A mysqli object returned by mysqli_connect or mysqli_init

hostname

Can be either a host name or an IP address. When passing null, the value is retrieved from mysqli.default_host. When possible, pipes will be used instead of the TCP/IP protocol. The TCP/IP protocol is used if a host name and port number are provided together e.g. localhost:3308.

username

The MySQL username or null to assume the username based on the mysqli.default_user ini option.

password

The MySQL password or null to assume the password based on the mysqli.default_pw ini option.

database

The default database to be used when performing queries or null.

port

The port number to attempt to connect to the MySQL server or null to assume the port based on the mysqli.default_port ini option.

socket

The socket or named pipe that should be used or null to assume the socket based on the mysqli.default_socket ini option.

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 hostname 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.

Return Values

Returns true on success or false on failure.

Errors/Exceptions

If mysqli error reporting is enabled (MYSQLI_REPORT_ERROR) and the requested operation fails, a warning is generated. If, in addition, the mode is set to MYSQLI_REPORT_STRICT, a mysqli_sql_exception is thrown instead.

Changelog

Version	Description
7.4.0	All parameters are now nullable.

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::__construct();

        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