(PHP 5, PHP 7, PHP 8)
mysqli::change_user -- mysqli_change_user — Changes the user of the specified database connection
面向對象風(fēng)格
$username, string $password, ?string $database): bool過(guò)程化風(fēng)格
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.
mysql僅以過(guò)程化樣式：由mysqli_connect() 或 mysqli_init() 返回的 mysqli 對象。
usernameThe MySQL user name.
passwordThe MySQL password.
databaseThe 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.
成功時(shí)返回 true， 或者在失敗時(shí)返回 false。
示例 #1 mysqli::change_user() example
面向對象風(fēng)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();
?>
過(guò)程化風(fēng)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);
?>
以上例程會(huì )輸出：
Default database: world Value of variable a is NULL
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.