<PLEASE USE THIS TEMPLATE TO HELP YOU CREATE A GREAT POST!>
I have several questions about this task:
- why do we need an “a”?
- why AS is not used here?
- why do we put “a.” in the first SELECT?
- why do we need GROUP BY in inner query? it defines the way you see the output, isn`t it?
<Below this line, add a link to the EXACT exercise that you are stuck at.>
<Below this line, in what way does your code behave incorrectly? Include ALL error messages.>
<In this course, it often helps to include a screenshot of your whole web browser – that lets everyone see what you see. If you wish to include a screenshot, add it below this line.>
<If you wish to copy/paste in your code, you can use this next section. This will allow others to copy/paste your code for testing – something that they won’t be able to do with just a screenshot.>
AVG(a.flight_distance) AS average_distance
sum(distance) AS flight_distance
GROUP BY 1,2,3
GROUP BY 1,2
ORDER BY 1,2;
<do not remove the three backticks above>