I am no longer able to access my database after including WordPress functions in my index.php file.

I used the following WordPress functions to access the WordPress header and footer

<?php
    @require '../wp-load.php';
    get_header(); 
    get_footer(); 

I need to use the WordPress header and footer and also use my external database without conflicting with each other.

ISSUE

I properly access the WordPress header and footer but now my EXTERNAL database is no longer accessible

Kindly help