I think your three examples at the bottom, Data -> SQL -> Delver query, should all be on the same example. In the first table it's like a timesheet thing, in your SQL you're making a list of people and their number of purchases and in the third Delver query you're asking a number of questions.

I realize you might be aiming this application at people who actually can't read the SQL, but you're also saying "You're drowning in tedious reports." implying they actually use SQL and this is to replace it.

So make the examples consistent and give people some insight into how this works and what actual SQL query a question generates.