How to use datamapper to return table entries as a json formatted string?
Hash[Page.all( :fields => [:id, :title] ).map{|p|[p.id,p.title]}].to_json

DEBUG (0.000176) SELECT `id`, `title` FROM `pages` ORDER BY `id`
> {"1":"page A","2":"page B"}

Page.all( :fields => [:title] ).map(&:title).to_json

DEBUG (0.000038) SELECT `title` FROM `pages` ORDER BY `id`
> ["page A","page B"]