ASA SQL User's Guide
  Summarizing, Grouping and Sorting Query Results
    The ORDER BY clause: sorting query results

ORDER BY and GROUP BY

You can use an ORDER BY clause to order the results of a GROUP BY in a particular way.

Example 

The following query finds the average price of each product and orders the results by average price:

SELECT name, AVG(unit_price)
FROM product
GROUP BY name
ORDER BY AVG(unit_price)