(PHP 5)
mysqli::change_user -- mysqli_change_user — Changes the user of the specified database connection
Object oriented style
$user
, string $password
, string $database
)Procedural style
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.
linkProcedural style only: A link identifier returned by mysqli_connect() or mysqli_init()
user
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.
Returns TRUE on success or FALSE on failure.
Note:
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.
Example #1 mysqli::change_user() example
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();
?>
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);
?>
The above examples will output:
Default database: world Value of variable a is NULL