Question

I could just use a find_by_sql to accomplish this, but I’d like to do it the Rails way if possible.

My SQL query looks like this:

SELECT regions.id, max(updated_at) FROM demographics 
JOIN regions ON (regions.id = demographics.region_id) 
JOIN region_stats ON (region_stats.region_id = regions.id) 
WHERE region_stats.income_level = 1    
GROUP BY demographics.region_id;

Is there a way to convert this cleanly to Rails?

Answer 1

Untested:

Demographic.joins(:region => [:region_stats]).select('demographics.region_id, max(demographics.updated_at) as `max_date`').where(:region_stats => {:income_level => 1}).group('demographics.region_id')