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mysqli::change_user

mysqli_change_user

(PHP 5, PHP 7, PHP 8)

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

Descrizione

Stile orientato agli oggetti

public mysqli::change_user(string $username, #[\SensitiveParameter] string $password, ?string $database): bool

Stile procedurale

mysqli_change_user(
    mysqli $mysql,
    string $username,
    #[\SensitiveParameter] string $password,
    ?string $database
): bool

Attempts to connect to the specified database using the provided credentials.

In comparison to mysqli::connect(), this method will not disconnect the current connection if the new connection cannot be opened.

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.

Elenco dei parametri

link

Solo nello stile procedurale: un identificatore restituito da mysqli_connect() o mysqli_init()

username

The MySQL user name.

password

The MySQL password.

database

The database name. If null or an empty string is passed, the connection to the server will be opened with no default database.

Valori restituiti

Restituisce true in caso di successo, false in caso di fallimento.

Errori/Eccezioni

If mysqli error reporting is enabled (MYSQLI_REPORT_ERROR) and the requested operation fails, a warning is generated. If, in addition, the mode is set to MYSQLI_REPORT_STRICT, a mysqli_sql_exception is thrown instead.

Esempi

Example #1 Resetting the connection session

Stile orientato agli oggetti

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "test");

$mysqli->query("SET @a:=1");

$mysqli->change_user("my_user", "my_password", "world");

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

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

Stile procedurale

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "test");

mysqli_query($link, "SET @a:=1");

mysqli_change_user($link, "my_user", "my_password", "world");

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

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

I precedenti esempi visualizzeranno:

Default database: world
Value of variable a is NULL

Example #2 If database is null the connection is opened without selecting any default database

Stile orientato agli oggetti

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "test");

$mysqli->change_user("my_user", "my_password", null);

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

I precedenti esempi visualizzeranno:

Default database:

Note

Nota:

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.

Vedere anche: