construct

mysqli::__construct

mysqli::connect

mysqli_connect

Open a new connection to the MySQL server

ENTITY

ENTITY

ENTITY

mysqli

false

mysqli_connect

string

null

hostname

ENTITY

string

null

username

ENTITY

string

null

password

ENTITY

string

null

database

ENTITY

int

null

port

ENTITY

string

null

socket

ENTITY

Opens a connection to the MySQL Server.

ENTITY

hostname
Can be either a host name or an IP address. When passing ENTITY, 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.

Prepending host by p: opens a persistent connection. mysqli_change_user is automatically called on connections opened from the connection pool.

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

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

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

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

socket
The socket or named pipe that should be used or ENTITY 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.

ENTITY

mysqli::__construct always returns an object which represents the connection to a MySQL Server, regardless of it being successful or not.

mysqli_connect returns an object which represents the connection to a MySQL Server, ENTITY.

mysqli::connect returns ENTITY on successENTITY. Prior to PHP 8.1.0, returns ENTITY on success.

ENTITY ENTITY

As of PHP 8.5.0, calling the constructor on an already-constructed object throws an Error.

ENTITY

ENTITY

<?php

/* You should enable error reporting for mysqli before attempting to make a connection */
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);

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

/* Set the desired charset after establishing a connection */
$mysqli->set_charset('utf8mb4');

printf("Success... %s\n", $mysqli->host_info);

   

<?php

/* You should enable error reporting for mysqli before attempting to make a connection */
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);

$mysqli = mysqli_connect('localhost', 'my_user', 'my_password', 'my_db');

/* Set the desired charset after establishing a connection */
mysqli_set_charset($mysqli, 'utf8mb4');

printf("Success... %s\n", mysqli_get_host_info($mysqli));

   

Success... localhost via TCP/IP

<?php

class FooMysqli extends mysqli {
    public function __construct($host, $user, $pass, $db, $port, $socket, $charset) {
        mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
        parent::__construct($host, $user, $pass, $db, $port, $socket);
        $this->set_charset($charset);
    }
}

$db = new FooMysqli('localhost', 'my_user', 'my_password', 'my_db', 3306, null, 'utf8mb4');

   

<?php

error_reporting(0);
mysqli_report(MYSQLI_REPORT_OFF);
$mysqli = new mysqli('localhost', 'my_user', 'my_password', 'my_db');
if ($mysqli->connect_errno) {
    throw new RuntimeException('mysqli connection error: ' . $mysqli->connect_error);
}

/* Set the desired charset after establishing a connection */
$mysqli->set_charset('utf8mb4');
if ($mysqli->errno) {
    throw new RuntimeException('mysqli error: ' . $mysqli->error);
}

   

<?php

error_reporting(0);
mysqli_report(MYSQLI_REPORT_OFF);
$mysqli = mysqli_connect('localhost', 'my_user', 'my_password', 'my_db');
if (mysqli_connect_errno()) {
    throw new RuntimeException('mysqli connection error: ' . mysqli_connect_error());
}

/* Set the desired charset after establishing a connection */
mysqli_set_charset($mysqli, 'utf8mb4');
if (mysqli_errno($mysqli)) {
    throw new RuntimeException('mysqli error: ' . mysqli_error($mysqli));
}

   

ENTITY ENTITY

[!NOTE] ENTITY only: If the connection fails, an object is still returned. To check whether the connection failed, use either the mysqli_connect_error function or the mysqli-ENTITYconnect_error property as in the preceding examples.

[!NOTE] If it is necessary to set options, such as the connection timeout, mysqli_real_connect must be used instead.

[!NOTE] Calling the constructor with no parameters is the same as calling mysqli_init.

[!NOTE] Error "Can't create TCP/IP socket (10106)" usually means that the variables_order configure directive doesn't contain character E. On Windows, if the environment is not copied the SYSTEMROOT environment variable won't be available and PHP will have problems loading Winsock.

ENTITY

mysqli_real_connect, mysqli_options, mysqli_connect_errno, mysqli_connect_error, mysqli_close