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Development Tools Database Foundations SQL Calculating, Aggregating and Other Functions Grouping, Joining and Cleaning Up

I can't figure this out!

Question: Group all reviews by "movie_id" and get the average "score" and alias it as "average

My answer: SELECT movie_id AVG(score) AS average FROM movies GROUP BY movie_id

2 Answers

I think something like ...

SELECT AVG(score) AS average FROM reviews GROUP BY movie_id

... should do it.


Aah, I was quering the wrong database.

I think it would be helpful if we are told what schema (databases and tables) are available to us. Often times in this course, I had to guess the name of the database in the challenges. Most of the times, it carries over from one challenge to another, but sometimes I forget, and then its annoying cause its like throwing the basketball into the dark hoping to find a basket somewhere, if you know what I mean...

Thanks for your answer.

I agree that there are some challenges like that. I found a few courses too - especially in the Rails track where the code gets updated, or databases get created with no instruction how to do that yourself. I initially found it mega-frustrating but did eventually get through the problems. Although the last course I took I did just give up as the tutor was just flipping through multiple files deleting stuff seemingly at random with no explanation why!

I guess it can't be perfect!

Steve Hunter, I am doing some rails courses too. I see exactly what you are saying.