mysqli::__construct

mysqli::connect

mysqli_connect

(PHP 5, PHP 7, PHP 8)

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

Açıklama

Nesne yönelimli kullanım

public mysqli::__construct(
    ?string $hostname = null,
    ?string $username = null,
    #[\SensitiveParameter] ?string $password = null,
    ?string $database = null,
    ?int $port = null,
    ?string $socket = null
)

public mysqli::connect(
    ?string $hostname = null,
    ?string $username = null,
    #[\SensitiveParameter] ?string $password = null,
    ?string $database = null,
    ?int $port = null,
    ?string $socket = null
): bool

Yordamsal kullanım

mysqli_connect(
    ?string $hostname = null,
    ?string $username = null,
    #[\SensitiveParameter] ?string $password = null,
    ?string $database = null,
    ?int $port = null,
    ?string $socket = null
): mysqli|false

Opens a connection to the MySQL Server.

Bağımsız Değişkenler

hostname

Can be either a host name or an IP address. When passing null, 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 null to assume the username based on the mysqli.default_user ini option.

password

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

database

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

port

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

socket

The socket or named pipe that should be used or null to assume the socket based on the mysqli.default_socket ini option.

Bilginize:
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.

Dönen Değerler

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, başarısızlık durumunda false döner.

mysqli::connect() returns true on success başarısızlık durumunda false döner. Prior to PHP 8.1.0, returns null on success.

Hatalar/İstisnalar

Eğer mysqli hata bildirimi etkinse (MYSQLI_REPORT_ERROR) ve istenen işlem başarısız olursa bir uyarı üretilir. Ek olarak, kip MYSQLI_REPORT_STRICT ise bunun yerine mysqli_sql_exception istisnası oluşur.

Sürüm Bilgisi

Sürüm: Açıklama

8.1.0 mysqli::connect() now returns true instead of null on success.

7.4.0 All parameters are now nullable.

Sürüm:	Açıklama
8.1.0	mysqli::connect() now returns `true` instead of `null` on success.
7.4.0	All parameters are now nullable.

Örnekler

Örnek 1 mysqli::__construct() example

Nesne yönelimli kullanım

<?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);

Yordamsal kullanım

<?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));

The above examples will output something similar to:

Success... localhost via TCP/IP

Örnek 2 Extending mysqli class

<?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');

Örnek 3 Manual error handling

If error reporting is disabled, the developer is responsible for checking and handling failures

Nesne yönelimli kullanım

<?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);
}

Yordamsal kullanım

<?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));
}

Notlar

Bilginize:
MySQLnd daima sunucunun öntanımlı bir karakter kümesi olduğunu varsayar. Bu karakter kümesi, mysqlnd'nin kullanacağı uzlaşım/kimlik doğrulama bağlantısı sırasında gönderilir.
Libmysqlclient, ya my.cnf dosyasındaki öntanımlı karakter kümesini ya da mysqli_init() çağrısından sonraki ilk mysqli_real_connect() çağrısından önce çağrılan mysqli_options() işlevinde belirtilen karakter kümesini kullanır.

Bilginize:
Nesne yönelimli kullanım 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->connect_error property as in the preceding examples.

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

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

Bilginize:
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.

Ayrıca Bakınız

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