lucacerone/bc — pull request #2 by lucacerone (2014-08-13 20:42:22+00:00)
Title: Improvements to the novice sql lessons.

These are the modifications @pbanaszkiewicz and I agreed on as part of the Software Carpentry teaching session.

Piotr added a nice figure to lesson 1 showing graphically what fields, columns and records are.
We also modified a bit the text and clarifiied how the count() aggregator works in lesson 6.