Change_user

In this article, we will focus on the mysqli_change_user() function in PHP, which is used to change the user and/or password used to connect to a MySQL database. We will provide you with an overview of the function, how it works, and examples of its use.

Introduction to the mysqli_change_user() function

The mysqli_change_user() function is a built-in function in PHP that is used to change the user and/or password used to connect to a MySQL database. This function is useful when you need to switch to a different user with different privileges or when you need to change the password for an existing user.

How to use the mysqli_change_user() function

Using the mysqli_change_user() function is very simple. You just need to call the function and pass in a valid MySQLi object, the new username, and the new password as arguments. Here is an example:

<?php
$mysqli = new mysqli("localhost", "username", "password", "database");
if ($mysqli->connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli->connect_error;
    exit();
}

$mysqli->change_user("newusername", "newpassword");

// execute queries using the new user

$mysqli->close();
?>

In this example, we create a new MySQLi object and connect to a MySQL database with a username and password. We then call the change_user() function of the MySQLi object to switch to a different user with a different password. We can then execute queries using the new user.

Advanced usage

The mysqli_change_user() function can also be used in more advanced scenarios. For example, you can use the function to change the user and password for a specific connection within a MySQL session. Here is an example:

<?php
$mysqli = new mysqli("localhost", "username", "password", "database");
if ($mysqli->connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli->connect_error;
    exit();
}

$mysqli->query("SET @olduser = CURRENT_USER()");
$mysqli->change_user("newusername", "newpassword");
$mysqli->query("SET @newuser = CURRENT_USER()");
$mysqli->change_user("@olduser", "password");

// execute queries using the original user

$mysqli->close();
?>

In this example, we create a new MySQLi object and connect to a MySQL database with a username and password. We then execute a SET query to store the current user in a variable. We then call the change_user() function of the MySQLi object to switch to a different user with a different password and store the new user in a different variable. We then change back to the original user by passing the original user variable and password to the change_user() function. We can then execute queries using the original user.

Conclusion

In conclusion, the mysqli_change_user() function is a powerful tool for changing the user and/or password used to connect to a MySQL database in PHP. By understanding how to use the function and its advanced usage scenarios, you can take advantage of this feature to create powerful and secure MySQL connections in your PHP scripts.