On Thu, Jan 22, 2009 at 1:58 PM, Max Williams < [email protected]> wrote:
> > After a bit of experimentation i confirmed for myself that that is > indeed the case :) > > thanks a lot Andrew, this is great. I'd seen named scopes before but > never really used them much and never realised their potential for > managing includes. > > One thing i noticed which is interesting...lessons are joined to assets > through a join table, 'elements'. > > if i use the with_assets scope for an association that goes through a > join table, then rails does a further join to the assets table, like > you'd expect with an include, so we have this situation: > > user JOIN user_usb_lessons JOIN lessons JOIN elements JOIN assets > > If, however, it's a simple association (such as user.lessons, which just > uses Lesson's user_id field) then rails splits it off into three sql > calls: the first to load the lessons, the second to load the elements > (join table records) and the third to load the assets. > > I guess that three seperate simple calls were seen as preferable to a > single JOIN? > > Anyway, thanks again! > max > -- > Posted via http://www.ruby-forum.com/. > > > > Yes, on more complicated joins, where Rails thinks it will be better, it does split the query into multiple queries. -- Andrew Timberlake http://ramblingsonrails.com http://www.linkedin.com/in/andrewtimberlake "I have never let my schooling interfere with my education" - Mark Twain --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
