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The MySQLi class

<<mysqli->connect_error -- mysqli_connect_error

mysqli::debug -- mysqli_debug>>

mysqli::__construct

mysqli_connect

(PHP 5)

mysqli::__construct -- mysqli_connectOpen a new connection to the MySQL server

Beschreibung

Objektorientierter Stil

mysqli::__construct() ([ string $host = ini_get("mysqli.default_host") [, string $username = ini_get("mysqli.default_user") [, string $passwd = ini_get("mysqli.default_pw") [, string $dbname = "" [, int $port = ini_get("mysqli.default_port") [, string $socket = ini_get("mysqli.default_socket") ]]]]]] )

Prozeduraler Stil

mysqli mysqli_connect ([ string $host = ini_get("mysqli.default_host") [, string $username = ini_get("mysqli.default_user") [, string $passwd = ini_get("mysqli.default_pw") [, string $dbname = "" [, int $port = ini_get("mysqli.default_port") [, string $socket = ini_get("mysqli.default_socket") ]]]]]] )

Opens a connection to the MySQL Server running on.

Parameter-Liste

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.

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

username

The MySQL user name.

passwd

If not 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.

Hinweis:

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.

Rückgabewerte

Returns an object which represents the connection to a MySQL Server.

Changelog

Version Beschreibung
5.3.0 Added the ability of persistent connections.

Beispiele

Beispiel #1 mysqli::__construct() example

Objektorientierter Stil

<?php
$mysqli 
= new mysqli('localhost''my_user''my_password''my_db');

/*
 * This is the "official" OO way to do it,
 * BUT $connect_error was broken until PHP 5.2.9 and 5.3.0.
 */
if ($mysqli->connect_error) {
    die(
'Connect Error (' $mysqli->connect_errno ') '
            
$mysqli->connect_error);
}

/*
 * Use this instead of $connect_error if you need to ensure
 * compatibility with PHP versions prior to 5.2.9 and 5.3.0.
 */
if (mysqli_connect_error()) {
    die(
'Connect Error (' mysqli_connect_errno() . ') '
            
mysqli_connect_error());
}

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

$mysqli->close();
?>

Objektorientierter Stil when extending mysqli class

<?php

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

        if (
mysqli_connect_error()) {
            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();
?>

Prozeduraler Stil

<?php
$link 
mysqli_connect('localhost''my_user''my_password''my_db');

if (!
$link) {
    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

Anmerkungen

Hinweis:

MySQLnd always assumes the server default charset. This charset is sent during connection hand-shake/authentication, which mysqlnd will use.

Libmysql 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().

Hinweis:

OO syntax only: If a connection fails an object is still returned. To check if the connection failed then use either the mysqli_connect_error() function or the mysqli->connect_error property as in the preceding examples.

Hinweis:

If it is necessary to set options, such as the connection timeout, mysqli_real_connect() must be used instead.

Hinweis:

Calling the constructor with no parameters is the same as calling mysqli_init().

Hinweis:

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.

Siehe auch


3 BenutzerBeiträge:
- Beiträge aktualisieren...
Anonymous
14.09.2009 2:37
If you get an error like
  Can't connect to MySQL server on 'localhost' (10061)
and you use named pipes/socket connections (or aren't sure how you installed the MySQL server) try the following connect command:

<?php
mysqli_connect
('.', $user_name, $password, $database_name, null, 'mysql');
?>

The '.' as hostname is absolutely necessary when using named pipes. 'localhost' won't work. 'mysql' is the standard name for the pipe/socket.
Slavyansk2.ru
26.09.2008 7:14
If you have error like "Trying to clone an uncloneable object of class..." when trying connect, add record

php_value zend.ze1_compatibility_mode 0

in your .htaccess file. This resolve connection problem.
chip1977 at mail dot ru
28.01.2008 13:52
To specify charset in my.cnf file you just have to add
skip-character-set-client-handshake directive after
[mysqld]
default-character-set=utf8



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