PHP Manual
mysqli
Changes the user of the specified database connection

mysqli::change_user

mysqli_change_user

(PHP 5, PHP 7, PHP 8)

mysqli::change_user -- mysqli_change_user — Changes the user of the specified database connection

Beschreibung

Objektorientierter Stil

public mysqli::change_user(string $username, string $password, ?string $database): bool

Prozeduraler Stil

mysqli_change_user(
    mysqli $mysql,
    string $username,
    string $password,
    ?string $database
): bool

Changes the user of the specified database connection and sets the current database.

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.

Parameter-Liste

mysql

Nur bei prozeduralem Aufruf: Ein von mysqli_connect() oder mysqli_init() zurückgegebenes mysqli-Objekt.

username

The MySQL user name.

password

The MySQL password.

database

The database to change to.

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

Rückgabewerte

Gibt bei Erfolg true zurück. Bei einem Fehler wird false zurückgegeben.

Beispiele

Beispiel #1 mysqli::change_user() example

Objektorientierter Stil


<?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();
?>

Prozeduraler Stil


<?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);
?>

Die obigen Bespiele erzeugen folgende Ausgabe:

Default database: world
Value of variable a is NULL

Anmerkungen

Hinweis:
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.