This is so well done, I'm kind of sad that it isn't getting more attention. I love the concept. My one bit of feedback is that the SQL query text area should have a button to execute the query, rather than clearing the results table and analyzing the query as I type. In the exercise on updating records, it was difficult for me to write the UPDATE statement because I wanted to look at the rows I was updating. I'd prefer if it left the results from the previous query up until the next query runs. Or if you could just leave the same results up the whole time and you could visually see the update run and highlight the rows/columns that were updated and see the values change in place.