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mysqli_change_user

(PHP 5 CVS only)

mysqli_change_user

(no version information, might be only in CVS)

mysqli->change_user -- Changes the user of the specified database connection

Description

Procedural style:

bool mysqli_change_user ( object link, string user, string password, string database)

Object oriented style (method):

class mysqli {

bool change_user ( string user, string password, string database)

}

mysqli_change_user() is used to change the user of the specified database connection as given by the link parameter and to set the current database to that specified by the database parameter.

If desired, the NULL value may be passed in place of the database parameter resulting in only changing the user and not selecting a database. To select a database in this case use the mysqli_select_db() function.

In order to successfully change users a valid username and password parameters must be provided and that user must have sufficient permissions to access the desired database. If for any reason authorization fails, the current user authentication will remain.

注: Using this command will always cause the current database connection to behave as if was a completely new database connection, regardless of if the operation was completed successfully. This reset includes performing a rollback on any active transactions, closing all temporary tables, and unlocking all locked tables.

Return Values

如果成功则返回 TRUE，失败则返回 FALSE。

See also:

mysqli_connect() mysqli_select_db()

Example

例子 1. Object oriented style

<?php

/* connect database test */
$mysqli = new mysqli("localhost", "my_user", "my_password", "test");

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

/* Set Variable a */
$mysqli->query("SET @a:=1");
                                         
/* reset all and select a new database */
$mysqli->change_user("my_user", "my_password", "world");

if ($result = $mysqli->query("SELECT DATABASE()")) {
    $row = $result->fetch_row();
    printf("Default database: %s\n", $row[0]);
    $result->close();
}

if ($result = $mysqli->query("SELECT @a")) {
    $row = $result->fetch_row();
    if ($row[0] === NULL) {
        printf("Value of variable a is NULL\n");
    }
    $result->close();
}

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

例子 2. Procedural style

<?php
/* connect database test */
$link = mysqli_connect("localhost", "my_user", "my_password", "test");

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

/* Set Variable a */
mysqli_query($link, "SET @a:=1");
                                         
/* reset all and select a new database */
mysqli_change_user($link, "my_user", "my_password", "world");

if ($result = mysqli_query($link, "SELECT DATABASE()")) {
    $row = mysqli_fetch_row($result);
    printf("Default database: %s\n", $row[0]);
    mysqli_free_result($result);
}

if ($result = mysqli_query($link, "SELECT @a")) {
    $row = mysqli_fetch_row($result);
    if ($row[0] === NULL) {
        printf("Value of variable a is NULL\n");
    }
    mysqli_free_result($result);
}

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

The above examples would produce the following output: 

Default database: world
Value of variable a is NULL


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