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

说明

面向对象风格

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

过程化风格

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.

参数

mysql

仅以过程化样式：由mysqli_connect() 或 mysqli_init() 返回的 mysqli 对象。

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.

返回值

成功时返回 true， 或者在失败时返回 false。

范例

示例 #1 mysqli::change_user() example

面向对象风格

<?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();
?>

过程化风格

<?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);
?>

以上例程会输出：

Default database: world
Value of variable a is NULL

注释

注意:

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.

参见