php8.5
Home/ Manual/ mysql / functions/ mysql_connect

mysql_connect

PHP function Edit on GitHub ✎

(PHP 4, PHP 5)

Open a connection to a MySQL Server

Note mysqli_connectPDO::__construct

Description

mysql_connect(string $server = ini_get("mysql.default_host"), string $username = ini_get("mysql.default_user"), string $password = ini_get("mysql.default_password"), bool $new_link = false, int $client_flags = 0): resource|false

Opens or reuses a connection to a MySQL server.

Parameters

server

The MySQL server. It can also include a port number. e.g. "hostname:port" or a path to a local socket e.g. ":/path/to/socket" for the localhost.

If the PHP directive mysql.default_host is undefined (default), then the default value is 'localhost:3306'. In Sqlsafemode, this parameter is ignored and value 'localhost:3306' is always used.

username

The username. Default value is defined by mysql.default_user. In Sqlsafemode, this parameter is ignored and the name of the user that owns the server process is used.

password

The password. Default value is defined by mysql.default_password. In Sqlsafemode, this parameter is ignored and empty password is used.

new_link

If a second call is made to mysql_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned. The new_link parameter modifies this behavior and makes mysql_connect() always open a new link, even if mysql_connect() was called before with the same parameters. In Sqlsafemode, this parameter is ignored.

client_flags

The client_flags parameter can be a combination of the following constants: 128 (enable LOAD DATA LOCAL handling), MYSQL_CLIENT_SSL, MYSQL_CLIENT_COMPRESS, MYSQL_CLIENT_IGNORE_SPACE or MYSQL_CLIENT_INTERACTIVE. Read the section about mysql.client-flags for further information. In Sqlsafemode, this parameter is ignored.

Return Values

Returns a MySQL link identifier on successFalseforfailure.

Examples

mysql_connect() example

php
<?php
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link) {
    die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);
?>

mysql_connect() example using hostname:port syntax

php
<?php
// we connect to example.com and port 3307
$link = mysql_connect('example.com:3307', 'mysql_user', 'mysql_password');
if (!$link) {
    die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);

// we connect to localhost at port 3307
$link = mysql_connect('127.0.0.1:3307', 'mysql_user', 'mysql_password');
if (!$link) {
    die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);
?>

mysql_connect() example using ":/path/to/socket" syntax

php
<?php
// we connect to localhost and socket e.g. /tmp/mysql.sock

// variant 1: omit localhost
$link = mysql_connect(':/tmp/mysql', 'mysql_user', 'mysql_password');
if (!$link) {
    die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);


// variant 2: with localhost
$link = mysql_connect('localhost:/tmp/mysql.sock', 'mysql_user', 'mysql_password');
if (!$link) {
    die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);
?>

Notes

Note

Whenever you specify "localhost" or "localhost:port" as server, the MySQL client library will override this and try to connect to a local socket (named pipe on Windows). If you want to use TCP/IP, use "127.0.0.1" instead of "localhost". If the MySQL client library tries to connect to the wrong local socket, the correct path should be set as mysql.default_host in Ini and the server field left blank.

Note

The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling mysql_close().

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.

See Also

Source: reference/mysql/functions/mysql-connect.xml · from the official PHP manual (php/doc-en)