Inner SELECT-s in Rails

rubyonrails-talk
1

Roland Mai wrote:

here you go:

select count(*) from (select distinct field_id from my_table       left join my_other_table on my_other_table.forein_key_id = my_table.id       where field_id < 5) as a left join some_other_table on a.other_id = some_other_table.id where some_other_table.created_at < getdate()

Hi, yahoo search brought me to this old topic, but I am running into the same problem. So is find_by_sql the only way to perform joins on inner-selects?

2

Depends on how you layout your models. Things like "left join my_other_table on my_other_table.forein_key_id = my_table.id" are taken care of by AR if you set up the associations properly. You could then do a Model.count(:joins=>..., :conditions=>....)