Rails: select unique values from a column

Question

I already have a working solution, but I would really like to know why this doesn\'t work:

ratings = Model.select(:rating).uniq
ratings.each { |r| puts r.rat         


        

Answer 1

If you want to also select extra fields:

Model.select('DISTINCT ON (models.ratings) models.ratings, models.id').map { |m| [m.id, m.ratings] }