When trying to view the databases from the cPanel interface of an account, you might end up with no values at all. However, if you check the backend, you can find that these database folders consumes space.
To fix this issue, SSH to the server and open the file : /var/cpanel/cpanel.config and make sure the variable disk_usage_include_sqldbs is set to 1 ( instead of 0 )
Once that change is made, hit the following from the shell :
# /scripts/update_db_cache
This should fix the issue !