How to select data from DB for custom field?

I am trying to use Tally Graph to display a chart in my sidebar. I am not sure if it’s the right plugin for me, but it’s the best I can find.

I have a database with a series of fields. The only data is either -1, 0, or 1. The idea is to take this data and graph it over time, but the plugin requires you to manually enter it in a custom field (I have a bunch of fields and this would get tedious).

Is there a way to automatically pull all the data from the database and automatically insert it into a custom field? Or is there a better plugin that I could use? Or should I start learning PHP? ??