mysqli
PHP Manual

mysqli_connect

mysqli->__construct()

(No version information available, might be only in CVS)

mysqli->__construct() — Open a new connection to the MySQL server

说明

Procedural style

mysqli mysqli_connect ([ string $host [, string $username [, string $passwd [, string $dbname [, int $port [, string $socket ]]]]]] )

Object oriented style (constructor):

mysqli
__construct ([ string $host [, string $username [, string $passwd [, string $dbname [, int $port [, string $socket ]]]]]] )

Opens a connection to the MySQL Server running on.

参数

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.

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.

Note: 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.

返回值

Returns a object which represents the connection to a MySQL Server or FALSE if the connection failed.

范例

Example#1 Object oriented style

<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

printf("Host information: %s\n", $mysqli->host_info);

/* close connection */
$mysqli->close();
?>

Example#2 Procedural style

<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

/* check connection */
if (!$link) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

printf("Host information: %s\n", mysqli_get_host_info($link));

/* close connection */
mysqli_close($link);
?>

上例将输出：

Host information: Localhost via UNIX socket

注释

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.

mysqli
PHP Manual