Performing nested queries in rails

rubyonrails-talk
1

I am fairly new to rails and trying to learn rails by creating some projects on my own. I am trying to perform a geo search on a restaurant model and I am using geokit for that. My model stores the latitude and longitude for the location.

I am searching for the specified location entered by the user and getting all the restaurants that are near that location. However I would also like to apply another filter on the returned result like returning the restaurant that only serves italian (for example). Here is a snippet of the code that I using.

    @location = Geokit::Geocoders::GoogleGeocoder.geocode (params[:location])

    //Using geokit find method to return the restaurants within 2 miles of the specified address     @restaurants = Restaurant.find(:all, :origin => @location, :within => 2) //finally getting the restaurants that serve the user specified cuisine     @restaurants = @restaurants.where("cuisine like ?", params[:cuisine]) if params[:cuisine]

This results in an " undefined method `where' " error.

I am not able to figure out how can I get this to work. I am using rails3 and ruby 1.9.2.

Any help on this will be greatly appreciated.

Thanks, vishy

2

Response inline below:

I am fairly new to rails and trying to learn rails by creating some projects on my own. I am trying to perform a geo search on a

restaurant model and I am using geokit for that. My model stores the latitude and longitude for the location.

I am searching for the specified location entered by the user and getting all the restaurants that are near that location. However I

would also like to apply another filter on the returned result like returning the restaurant that only serves italian (for example). Here is a snippet of the code that I using.

@location = Geokit::Geocoders::GoogleGeocoder.geocode

(params[:location])

//Using geokit find method to return the restaurants within 2 miles of the specified address @restaurants = Restaurant.find(:all, :origin => @location, :within => 2) //finally getting the restaurants that serve the user specified

cuisine @restaurants = @restaurants.where(“cuisine like ?”, params[:cuisine]) if params[:cuisine]

Where method is available on Model class. http://guides.rubyonrails.org/active_record_querying.html#pure-string-conditions

Use

@restaurants = Restaurant.where(“cuisine like ?”,params[:cuisine]) if params[:cuisine]

3

If possible try with :conditions parameter.

T.Veeraa

4

Restaurant.where(:cuisine => params[:cuisine]) will return all the Restaurants that that have the cuisine. However I am trying to filter the returned results from @restaurants = Restaurant.find(:all, :origin => @location, :within => 2) . Hence I am trying to apply the where condition on @restaurants, using @restaurants = @restaurants.where("cuisine like ?", params[:cuisine]). But that doesn't work.

5

[...] Hence I am trying to apply the where condition on @restaurants, using @restaurants = @restaurants.where("cuisine like ?", params[:cuisine]). But that doesn't work.

Once you've gotten @restaurants you are not querying the DB anymore, hence the 'where' should give you an error. @restaurants is in essence an array and will not have a 'where' method in it unless you add it. Look into the Ruby methods for Array (http://ruby-doc.org/core/classes/ Array.html) and you'll probably find what you're looking for.

6

AR.find(:all) returns an array. Ar.where returns an ActiveRecord::Relation proxy which can be enumerate after calling `all` method.

I think that you have few options.

a) reverse the logice because `find` can be called on relation (I think...) :

@restaurants = Restaurant.scoped @restaurants = @restaurants.where("cuisine like ?", params[:cuisine]) if params[:cuisine] @restaurants = @restaurants.find(:all, :origin => @location, :within => 2)

This assumes that geokit extend ActiveRecord::Relation#find also, not only ActiveRecord::Base#find.

b) put the logic into find conditions = params[:cuisine] ? Restaurant.where("cuisine like ?", params[:cuisine]) : {} @restaurants = Restaurant.find(:all, :origin => @location, :within => 2, :conditions => conditions)

c) use with_scope condition = params[:cuisine] ? Restaurant.where("cuisine like ?", params[:cuisine]) : Restaurant.scoped Restaurant.with_scope(:find => condition) do   @restaurants = Restaurant.find(:all, :origin => @location, :within => 2) end

with_scope might be a private method in which case you should call it using 'send'

I hope that at least one option should work fine.

Robert Pankowecki