Sivakumar couldn’t make it to Convergence this year so he stayed home and pouted…or rather built a very cool Dynamics GP 2010 R2 Database SDK documenting GP objects in an easy to use manner.
Dynamics GP 2010 R2 Database SDK | Interesting Findings & Knowledge Sharing
SQL & DataGP 2010
Archived post from 2012. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.