How to change database password in php

As a PHP developer, maintaining the database is an important part of our daily work. In the process of developing a website, we usually need to connect to the database, perform queries, insert data, update data, etc. In order to ensure data security, we need to change the database password regularly. Below is a short tutorial on how to change database password in php.

Step 1: Connect to the database

First, we need to use the mysqli_connect() function or PDO constructor to connect to the database. Before connecting, we need to know the username and password for the database. For example:

$servername = "localhost";
$username = "myusername";
$password = "mypassword";
$dbname = "mydatabase";

// 使用mysqli_connect来连接到数据库
$conn = mysqli_connect($servername, $username, $password, $dbname);

// 或者使用PDO构造函数来连接到数据库
try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    // 设置PDO错误模式为异常
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch(PDOException $e) {
    echo "连接失败：" . $e->getMessage();
}

Step 2: Modify the database password

After connecting to the database, we need to use SQL commands to modify the database password. In MySQL, we can use the following command:

ALTER USER 'username'@'localhost' IDENTIFIED BY 'new_password';

where username is the user you want to modify, localhost is the host name of the user, and new_password is the new password you want to set. For example, if we want to change the user name of myusername and the password of the user whose host name is localhost to new_password, we can use the following command:

ALTER USER 'myusername'@'localhost' IDENTIFIED BY 'new_password';

It should be noted that if you are using an old version of MySQL, you may need to Use the SET PASSWORD command to change the password. For example, if you use MySQL 5.7 or higher, you can use the following command:

SET PASSWORD FOR 'myusername'@'localhost' = PASSWORD('new_password');

Step 3: Update the PHP code

After changing the database password, we need to update the PHP code connection information. For example, if we use the mysqli_connect() function to connect to the database, then we only need to update the $password variable to the new password:

// 修改数据库密码后更新密码变量
$password = "new_password";

// 使用mysqli_connect来连接到数据库
$conn = mysqli_connect($servername, $username, $password, $dbname);

If we use the PDO constructor to connect to the database, then we also need to update the password variable, and call PDO's setPassword() function to set a new password:

// 修改数据库密码后更新密码变量
$password = "new_password";

// 使用PDO构造函数来连接到数据库
try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    // 调用PDO的setPassword函数设置新密码
    $conn->exec("SET PASSWORD = '$password'");
    // 设置PDO错误模式为异常
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch(PDOException $e) {
    echo "连接失败：" . $e->getMessage();
}

So far, we have completed the steps to modify the database password in PHP. With this tutorial, you can regularly change your database password to protect your data security.

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