I was curious if it's useful to add the "answer output" (not SQL code) at the end of each question (e.g., it should return a value of "9" or X rows, etc.). This way, we can be sure that we are on the right track.

Hi Jahurul! Thanks for reaching out. Thanks for the suggestion. As for now, we believe providing the solutions is good enough for comparing the relevant result sets. Nevertheless, we will take your idea into account the next time we are updating the course. Thank you. Kind regards, Best, Tsvetelin

I like Jahurul's suggestion here. I liked the few exercises that provided the correct output ("should return x rows") the best. It is a little tedious to download and then unzip every single assignment to compare code. I prefer to see what the result should be and try to fix my code until it works, with the attached code being the last resort if I can't figure it out.