mysqli_change_user

Changes the user of the specified database connection (PHP 5)
bool mysqli_change_user ( mysqli link, string user, string password, string database )

Procedural style:

Object oriented style (method):

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.

返回值

如果成功则返回 TRUE,失败则返回 FALSE

范例

例 1250. 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 1251. 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);
?>

上例将输出:

Default database: world
Value of variable a is NULL