How to convert following query in rails 3 active record query?

Question

I want to find last 20 days latest data from audit table for that I have written following MySQL query:

 SELECT * 
 from   (select * from audits ORDER BY id DESC) as x 
 where  (auditable_type = 'Investment' 
 and    auditable_id =41 
 and    created_at <= '2011-12-01' AND  created_at >= '2011-11-25')  
 group by date(created_at)

I want to convert it to rails 3 active record query, how should I do so I will get same result from both the queries?

Answer 1

I don't think you can get much better than that (without using some gems like meta_where ):

Audits.where(
    'DATE(created_at) <= ? AND DATE(created_at) >= ? 
     AND auditable_type = ? AND auditable_id = ?',
    Date.new(2011, 12, 01), Date.new(2011, 11, 25), 'Investement', 41
).group('DATE(created_at)').order('id DESC')