PHP Connection failed: SQLSTATE[HY000] [2002] Connection refused

The error message "SQLSTATE[HY000] [2002] Connection refused" typically indicates that the client was unable to establish a connection to the database server. This can be due to several reasons, such as:

1. The database server is not running.
2. The database server is not running on the correct host or port.
3. There is a firewall blocking access to the database server.
4. The credentials (username and password) used to connect to the database are incorrect.

To troubleshoot the problem, you should check the following:

1. Verify that the database server is running.
2. Check that the database server is running on the correct host and port. You can do this by checking the configuration of your database client (e.g., in a configuration file or your code).
3. Check for any firewall rules that may be blocking access to the database.
4. Verify that the credentials used to connect to the database are correct. Ensure the username and password are correct, and the user has the necessary permissions to access the database.

If you still have problems after checking these items, there may be a problem with the database server itself or the network connection between the server and the client. In this case, you may need to contact the system administrator or the database administrator for further assistance.