(PHP 5, PHP 7, PHP 8)
mysqli::change_user -- mysqli_change_user — Changes the user of the specified database connection
面向对象风格
过程化风格
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
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.
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.
示例 #1 mysqli::change_user() example
面向对象风格
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "test");
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$mysqli->query("SET @a:=1");
$mysqli->change_user("my_user", "my_password", "world");
if ($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();
}
$mysqli->close();
?>
过程化风格
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "test");
if (!$link) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
mysqli_query($link, "SET @a:=1");
mysqli_change_user($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);
}
mysqli_close($link);
?>
以上示例会输出:
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.