The average length of films by category
From the previous exercise you've learned that the tables film and category have the necessary information to calculate the average movie length for every category. You've also learned that they share a common field film_id which can be used to join these tables. Now you will use this information to query a list of average length for each category.
Este exercício faz parte do curso
Applying SQL to Real-World Problems
Instruções do exercício
- Calculate the average
lengthand return this column asaverage_length. - Join the two tables
filmandcategory. - Ensure that the result is in ascending order by the average length of each category.
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
-- Calculate the average_length for each category
SELECT category,
___ AS average_length
FROM ___ AS f
-- Join the tables film & category
INNER JOIN ___ AS c
ON f.___ = c.___
GROUP BY ___
-- Sort the results in ascending order by length
___;