Everyone, I have two tables (assuming their most logical types): apartments id address bedrooms bathrooms googlemaps_id googlemaps id url the models: class Apartment < ActiveRecord::Base has_one :googlemap end class Googlemap < ActiveRecord::Base belongs_to :listing end I would like to find_all by searching the attributes in apartment, and also return the google map associated with that apartment, and a null (or empty string) if there's no google map in its table associated with the apartment's id. In sql I would do this with a left join, and while I could used the find_by_sql method I was wondering if there's a more practical "Rails" way of doing this. In the apartments controller I have something for found results like def results @apartments = Listing.find(:all, :conditions => ["bedrooms=? AND bathrooms=?", :params]) end But that will only return the columns in Apartments. How would I do that to get the googlemaps url if there is a corresponding value? Thanks all! - Joel
on 2006-03-02 20:51
on 2006-03-02 21:03
> I would like to find_all by searching the attributes in apartment, and > bathrooms=?", :params]) > end > > But that will only return the columns in Apartments. How would I do > that to get the googlemaps url if there is a corresponding value? First of all, your model name is Apartment, not Listing, so the code you have above should only return an error. But that aside... When you specified the has_one and belongs_to in your models, you told Rails how to set up the left join. This means you don't need to do it yourself. Any Apartment object will have a class method called googlemap. This is how you get the corresponding googlemap. @apartment = Apartment.find(:first) @apartment.googlemap Now, if you know for sure that you are going to use the googlemap, and you don't want rails to use two sql statements (which it would using the above code), then you can use the :include symbol to specify what we call "eager loading". Eager loading just means "go ahead and do the join cuz I know I'm gonna need it". @apartment = Apartment.find(:first, :include => :googlemap) @apartment.googlemap -Derrick S.