Railsでgroup->order->countしたい話

> Model.group(:column_name).order(count_column_name: "DESC").count(:column_name)

SELECT 
COUNT("model"."column_name") AS count_column_name, 
"model"."column_name" AS model_column_name
FROM "model" 
GROUP BY "model"."column_name" 
ORDER BY "count_column_name" DESC

できた。