database not found (but can access WP-ADMIN)

Hi,

I have checked all the other previous posts related to this topic.
Problem:

I have restored a database. I can access the wp-admin site but cannot access other parts of the site.

if I type site.com/wp-admin it works
But if I try to access site.com/wp-admin/page.php I get a database connection error.

If I try to access site.com I get the same error.
Also when I try to access site.com/index.php I get the same error.

Since I can access the wp-admin page, the database credentials in wp-config are surely right.

I have checked file permissions but they seem to be fine.

Any ideas?
Thanks in advance