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Databases Reporting with SQL Aggregate and Numeric Functions Practice Session

Jonatan Spahn
Jonatan Spahn
6,362 Points

User Average Rating, a little more advanced using subqueries

So I'm in the SQL Playground for the Aggregate and Numeric Functions (practice sessions) in the Reporting with SQL section.

What I would like to do is a join which states all movies that have been rated that are not SCI Fi. I was able to state the movies that have been rated here is the code:

SELECT title As Movie_Title, ROUND(AVG(rating),1) As Average_Rating FROM movies INNER JOIN reviews ON movies.ID = reviews.movie_id GROUP BY movie_id;

So I would like to narrow this and return movies that are not Sci Fi, I was thinking a subqury would do the trick but I can't figure it out. Here is what I have tried so far...

SELECT title As Movie_Title, ROUND(AVG(rating),1) As Average_Rating FROM movies IN (SELECT title FROM movies WHERE genre != "Sci Fi") INNER JOIN reviews ON movies.ID = reviews.movie_id GROUP BY movie_id;

SELECT title As Movie_Title, ROUND(AVG(rating),1) As Average_Rating FROM movies WHERE genre != "Sci Fi" INNER JOIN reviews ON movies.ID = reviews.movie_id GROUP BY movie_id;

1 Answer

Steven Parker
Steven Parker
228,991 Points

You don't need a sub-query.

Your WHERE clause will do the trick, but you have to place it correctly. It should come after the JOIN but before the GROUP BY.