CREATE TABLE Person (name VARCHAR, age INT, city TEXT, gender TEXT, job TEXT)
CREATE TABLE PersonFriend (name VARCHAR, friend VARCHAR, year INT)

Draw a bar chart for what is the average age for each gender?, and I want to show by the bars in desc.
SELECT gender, AVG(age) FROM Person GROUP BY gender ORDER BY gender DESC
SELECT "gender", AVG("age") FROM "Person" GROUP BY "gender" ORDER BY "gender" DESC NULLS LAST