Starting to learn sql

Hey folks!

this is the first time me ever asking something in a community, so i’m glad for any help. The screenshot i made was a challenge during the SQL learning course.

  1. Am I blind or did i do any mistake?
  2. I checked it four times, i can’t find any difference (except the efficiency differs), nevertheless sql still tells me that there is a mistake… how and why?

thank you upfront for your answers

best wishes


Hello, welcome to the forums! Yes, I think your code will work just fine. The problem is the CC learning environment can be very picky sometimes, and wants you to have the exact code shown in the hint. Not ideal, but some lessons seem to work that way…

I do think your code is better, though, so good job!


thank you very much :slightly_smiling_face:


It could be b/c your alias is called “sum” after you use sum() as an aggregate. Either remove the alias or call it something else.