mysqli::debug

[edit] Last updated: Fri, 17 May 2013

mysqli::__construct

mysqli_connect

(PHP 5)

mysqli::__construct -- mysqli_connect — Open a new connection to the MySQL server

Descrierea

Stil obiect-orientat

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") ]]]]]] )

Stil procedural

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.

Parametri

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.

Notă:
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.

Valorile întoarse

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

Istoria schimbărilor

Versiunea	Descriere
5.3.0	Added the ability of persistent connections.

Exemple

Example #1 mysqli::__construct() example

Stil obiect-orientat


<?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();
?>

Stil obiect-orientat 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();
?>

Stil procedural


<?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);
?>

Exemplele de mai sus vor afișa:

Success... MySQL host info: localhost via TCP/IP

Note

Notă:
MySQLnd întotdeauna preia setul de caractere implicit de pe server. Acest set de caractere este transmis în momentul stabilirii parametrilor/autentificării la conectare și este utilizat ulterior de mysqlnd.
Libmysql utilizează setul de caractere implicit stabilit în fișierul my.cnf sau printr-un apel explicit al funcției mysqli_options() înainte de apelul mysqli_real_connect(), dar după mysqli_init().

Notă:
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.

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

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

Notă:
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.

Vedeți de asemenea

mysqli_real_connect() - Opens a connection to a mysql server
mysqli_options() - Set options
mysqli_connect_errno() - Returns the error code from last connect call
mysqli_connect_error() - Returns a string description of the last connect error
mysqli_close() - Closes a previously opened database connection

mysqli::debug

mysqli::$connect_error

[edit] Last updated: Fri, 17 May 2013

add a note User Contributed Notes mysqli::__construct - [5 notes]

down

boukeversteegh at gmail dot com ¶

2 years ago


(php 5.3.3)



If $port is a string, such as "3306", mysqli::query() will not work, even though mysqli_connect_errno() reports no error (value 0)!



<?php

$mysqli = new mysqli("localhost", "user","password","database", "3306"); //port is a string!

$mysqli->query("SELECT 1;")->fetch_assoc();

// Fatal error: Call to a member function fetch_assoc() on a non-object

?>



This is particularly strange, since mysqli::query() should return a result object, or a boolean.



So, be careful when you read your port from a string or config file. Cast it to int first:

<?php

$port = (int)$port;

?>

down

Anonymous ¶

3 years ago


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.

down

Slavyansk2.ru ¶

4 years ago


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.

down

oleg at mastak dot fi ¶

29 days ago


If you want to connect to local named pipe on windows and you get error "php_network_getaddresses: getaddrinfo failed: No such host is known. ", even if you using using "." as host, please check your if you are using mysqlnd driver: If this is true, then probably you need to update to version 5.4 of php:



Named pipes support for Windows was added in PHP version 5.4.0.

@ http://php.net/manual/en/mysqlnd.overview.php 



Hopefully that will save you some time.

down

-1

chip1977 at mail dot ru ¶

5 years ago


To specify charset in my.cnf file you just have to add 

skip-character-set-client-handshake directive after 

[mysqld]

default-character-set=utf8

add a note