PHP mysql_connect function

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mysql_connect

(PHP 3, PHP 4, PHP 5)

Opens or reuses a connection to a MySQL 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 SQL safe mode, this parameter is ignored
and value ‘localhost:3306′ is always used.

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

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

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 SQL safe mode, this parameter is ignored.

The client_flags parameter can be a combination
of the following constants:
MYSQL_CLIENT_SSL,
MYSQL_CLIENT_COMPRESS,
MYSQL_CLIENT_IGNORE_SPACE or
MYSQL_CLIENT_INTERACTIVE.
Read the section about Table 2 for further information.
In SQL safe mode, this parameter is ignored.

Returns a MySQL link identifier on success, or FALSE on failure.

Example 1. mysql_connect() example

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

Example 2. mysql_connect() example using hostname:port syntax

// 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);

Example 3. mysql_connect() example using “:/path/to/socket” syntax

// we connect to localhost and socket e.g. /tmp/mysql.sock
 
//variant 1: ommit 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);

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, you should set the correct path as
mysql.default_host
string
in your PHP configuration and leave the server field
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:
You can suppress the error message on failure by prepending
a @
to the function name.