I have created on php file for establishing connection with database server. In this file, i am using `mysql_connect()` function with parameters host, username and password of my database server.

```
public class DatabaseConnect
{
function __construct()
{
    mysql_connect('localhost','username','password') or die('Could not connect to mysql server.');
    mysql_select_db('databasename');
}

}

```

Now in this case, username and password are visible to others.

I found one more way to secure the value i.e. `mysql.default_user` and `mysql.default_password`. In which scenario we have to this way?

Or how could i secure my values from others?