Rails 3.1 - find using count and select as

问题

I am trying to do the following sql statement in rails:

SELECT COUNT(downloads.title) AS total, downloads.title FROM `downloads` WHERE `downloads`.`member_id` = 60 Group by `downloads`.`title`

I wrote this in rails like this:

Download.where(:member_id => id).select("COUNT(downloads.title) AS total, downloads.title").group(:title)

If I run the query straight from the sql server the sql executes correctly but if I run the activerecord version I only get the title back.

I thought this might be because of attr_accessible but this doesnt seem to have made a difference.

any ideas ?

回答1:

Have you tried to call total method on the collection object ?
This information is not included in the output for object using to_s method, so you probably just do not see it, but total value is there.

downloads = Download.where(:member_id => id).select("COUNT(downloads.title) AS total, downloads.title").group(:title)
downloads.first.total

来源：https://stackoverflow.com/questions/8048987/rails-3-1-find-using-count-and-select-as