Here is an example of Wordpress being used to manage a database. Yes, blogs are simple databases, but this one is not like your usual blog.
Getup has set up a Wordpress blog to capture election promises. It's called Promise Watch.
Users can submit election promises they hear about and must enter the data in a template with clearly defined fields. The blog is then searchable by categories/fields for political party, and policy area.
With a little tweaking WP is very versatile.