(PHP 5)
mysqli->real_connect() — Opens a connection to a mysql server
Procedural style
Object oriented style (method)
Establish a connection to a MySQL database engine.
This function differs from mysqli_connect():
mysqli_real_connect() needs a valid object which has to be created by function mysqli_init().
With function mysqli_options() you can set various options for connection.
There is a flags parameter.
Procedural style only: A link identifier returned by mysqli_connect() or mysqli_init()
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.
The MySQL user name.
If 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).
If provided will specify the default database to be used when performing queries.
Specifies the port number to attempt to connect to the MySQL server.
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.
With the parameter flags you can set different connection options:
| Name | Description |
|---|---|
| MYSQLI_CLIENT_COMPRESS | Use compression protocol |
| MYSQLI_CLIENT_FOUND_ROWS | return number of matched rows, not the number of affected rows |
| MYSQLI_CLIENT_IGNORE_SPACE | Allow spaces after function names. Makes all function names reserved words. |
| MYSQLI_CLIENT_INTERACTIVE | Allow interactive_timeout seconds (instead of wait_timeout seconds) of inactivity before closing the connection |
| MYSQLI_CLIENT_SSL | Use SSL (encryption) |
Note: For security reasons the MULTI_STATEMENT flag is not supported in PHP. If you want to execute multiple queries use the mysqli_multi_query() function.
如果成功则返回 TRUE，失败则返回 FALSE。
Example#1 Object oriented style
<?php
/* create a connection object which is not connected */
$mysqli = mysqli_init();
/* set connection options */
$mysqli->options(MYSQLI_INIT_COMMAND, "SET AUTOCOMMIT=0");
$mysqli->options(MYSQLI_OPT_CONNECT_TIMEOUT, 5);
/* connect to server */
$mysqli->real_connect('localhost', 'my_user', 'my_password', 'world');
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
printf ("Connection: %s\n.", $mysqli->host_info);
$mysqli->close();
?>
Example#2 Procedural style
<?php
/* create a connection object which is not connected */
$link = mysqli_init();
/* set connection options */
mysqli_options($link, MYSQLI_INIT_COMMAND, "SET AUTOCOMMIT=0");
mysqli_options($link, MYSQLI_OPT_CONNECT_TIMEOUT, 5);
/* connect to server */
mysqli_real_connect($link, 'localhost', 'my_user', 'my_password', 'world');
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
printf ("Connection: %s\n.", mysqli_get_host_info($link));
mysqli_close($link);
?>
上例将输出：
Connection: Localhost via UNIX socket