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

Posted by Mikael paavola
Mikael paavola
1,786 Points

HAVING on an ALIAS

HAVING AVG(score) < 2;

has a different result than

HAVING average < 2;

This makes little sense to me as average is merely an alias of AVG(score). Can someone explain?

1 Answer

Tatiana Jamison
Tatiana Jamison
6,188 Points
Tatiana Jamison
Tatiana Jamison
6,188 Points

Hi Mikael,

Can you post your code and results? I just tried with the treehouse_movie_db from the course and the following query:

SELECT title, avg(score) AS average
FROM movies LEFT OUTER JOIN reviews
ON movies.id = reviews.movie_id
GROUP BY movie_id HAVING **condition**;

where condition was replaced with:

average < 2; returning Starman with avg 1.5

avg(score) < 2; returning Starman with avg 1.5

average > 3; returning Aliens (3.0732), Moulin Rouge (3.8333), Mama Mia (3.6154)

avg(score) > 3; returning Aliens (3.0732), Moulin Rouge (3.8333), Mama Mia (3.6154)

In other words, in my small trial, I got the same result whether I used the alias or the calculation. Hope to hear from you.