Can you divide one alias by another in MySQL?

Question

I have a multi-table query, similar to this (simplified version)

SELECT columns, count(table2.rev_id) As rev_count, sum(table2.rev_rating) As sum_rev_rating 
FRO         


        

Answer 1

You're not able to do calculations with aliases. One way of doing this would be to simply create another alias and order by that.

SELECT columns, count(table2.rev_id) As rev_count, sum(table2.rev_rating) As sum_rev_rating, sum(table2.rev_rating)/count(table2.rev_id) as avg_rev_rating
FROM table1
LEFT JOIN table2
ON table1.dom_id = table2.rev_domain_from 
WHERE dom_lastreview != 0 AND rev_status = 1 
GROUP BY dom_url 
ORDER BY avg_rev_rating DESC