Mysql Connection Problem

The error shown in your first post indicates MySQL is rejecting an empty username: the message reports a user like ''@'localhost'. That usually means the PHP call that opens the connection is receiving an empty string for the username (wrong variable name, not set, or overwritten). @samarinder's Connector/J note is for Java and not relevant here; @stephen84s's suggestion to test connectivity (telnet or CLI) is still a good step.

Quick checklist to find and fix the problem:

• Confirm WAMP's MySQL service is running (WAMP tray icon).
• Try logging in outside PHP: mysql -u root -p or use phpMyAdmin (bundled with WAMP) to verify a working account.
• Verify the PHP variables you pass to the connection call are not empty. If you are using $_POST/$_GET values make sure they exist before calling the connect function.
• Test TCP connectivity if needed: telnet 127.0.0.1 3306 (this only checks the port, not credentials).

Example fixes and safe setup (use mysqli or PDO rather than the old mysql extension):

$link = mysqli_connect('127.0.0.1', 'root', '');
if (! $link) {
    die('Connect error: ' . mysqli_connect_error());
}

If you need a dedicated web user, create one and grant minimal privileges from the MySQL console:

CREATE USER 'webuser'@'localhost' IDENTIFIED BY 'secret';
GRANT SELECT, INSERT, UPDATE ON school.* TO 'webuser'@'localhost';
FLUSH PRIVILEGES;

Notes and cautions: many WAMP installs use root with no password—if you supply a password when none exists you will also be denied. Check the MySQL account host (user@host) — user@localhost is different from user@127.0.0.1 and from user@%. Avoid running web apps as root; keep config files with credentials outside the web root.

See the PHP mysqli_connect docs for usage and the MySQL manual on account management for grant/authentication details: mysqli_connect documentation MySQL GRANT and account management.