On 19 Nov 2008, at 09:46, Günther Lackner wrote:
> > Hello! > > I need to speed up a count of apearances of a distinct category of > entities in a table. I get the categories with the following command: > > @asset_classes = ActiveRecord::Base.connection.select_values "SELECT > DISTINCT CLASS FROM SymbolsMatch_MASTER ORDER BY CLASS" > > Now I need to create a list of this categories together with the > number > of apearance in the table. Momentarily I use this syntax but it is > VERY > slow. > If you just want to count items then use DeviceToUpdate.count ... which will use an sql count rather than fetching the entire collection into memory and counting that (although arrays don't have a count method so i'm not sure how the code below is working at all). An appropriate index would also help counting, and/or you could cache the result Fred > > > > > <ul> > <% for asset_class in @asset_classes do %> > <% count = DeviceToUpdate.find(:all, :conditions => ["status like > 'moreinfo' and CLIENT_STATUS is NULL and CLASS like ?",asset_class ] > ).count > if count > 0 %> > <li> > <a href="<%= url_for(:controller => :more_info, :action => > :show_class, :class_name => asset_class) %>"><%= truncate(asset_class, > 20, ".") %> (<%= count.to_s %>)</a> > </li> > <% end %> > <% end %> > </ul> > > > > > > Thank you for any suggestion how to speed this up! > > lacky > -- > Posted via http://www.ruby-forum.com/. > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
