SQL-PQL (pronouced "Sequel Prequel") is an interactive SQL learning guide. It is developed using Ruby on Rails, Postgres SQL, Bootstrap, YAML, JQuery, Underscore.string, AJAX, OmniAuth, JST, EJS and hosted on Heroku.
In lesson two, example 4 shows up fine, but when you click on question 4 there is no problem statement even though there is a field to attempt a SQL query. A question needs to be inserted.