I understand you're encountering an error when trying to connect to a MySQL database using PHP's mysqli_connect() function. Let's break down the error message and provide a solution.

I'm mostly focused on web development with React and Next.js, but I can help you with this MySQL connection error. The error message "Access denied for user 'root'@'localhost' (using password: NO)" indicates that there's an issue with the database credentials you're using to connect. Here's what you can do to resolve this:

1. Check your database credentials:

   • Make sure you're using the correct username. In this case, it's trying to connect as 'root'.
   • The error message says "using password: NO", which means you haven't provided a password. If your MySQL server requires a password for the root user (which it should for security reasons), you need to provide it.

2. Verify your connection code: Here's an example of how your connection code should look:

   <?php $servername = "localhost"; $username = "root"; $password = "your_password_here"; $dbname = "your_database_name"; // Create connection $conn = new mysqli($servername, $username, $password, $dbname); // Check connection if ($conn->connect_error) { die("Connection failed: " . $conn->connect_error); } echo "Connected successfully"; ?>

   Make sure you replace "your_password_here" with the actual password for your root user, and "your_database_name" with the name of the database you're trying to connect to.

3. If you're certain that your root user doesn't have a password (which is not recommended for security reasons), you can try connecting without a password like this:

   $conn = new mysqli($servername, $username, "", $dbname);

4. If you continue to have issues, you may need to check your MySQL server configuration or consult with your database administrator to ensure that:

   • The MySQL server is running
   • The user 'root' has the necessary permissions to connect from localhost
   • There are no firewall or network issues preventing the connection

Remember, using the root user for application connections is generally not recommended for security reasons. It's better to create a specific user for your application with only the necessary permissions.

If you need more specific help with your database connection or if you're working on a web application and want to discuss best practices for data management in React or Next.js, feel free to ask!