ActiveRecord scope with association

rubyonrails-talk
1

rails 3.2.11

I have models

Airport   :name, :string   belongs_to city City   :name, :string   has_many airports   belongs_to country Country   :name, :string   has_many cities

and I want to search a particular airport through this association

  scope :search_airport, where(:name => name, :city => city, :country => country)

clearly this does not work

Could anyone show me how to set up a scope through association?

the input maybe only airport name, or airport name with city, or airport name with city and country name.

soichi

2

rails 3.2.11

I have models

Airport   :name, :string   belongs_to city City   :name, :string   has_many airports   belongs_to country Country   :name, :string   has_many cities

and I want to search a particular airport through this association

What do you mean by search an airport? Do you mean you want to find the airport with the given name, city, country?

  scope :search_airport, where(:name => name, :city => city, :country => country)

clearly this does not work

Could anyone show me how to set up a scope through association?

the input maybe only airport name, or airport name with city, or airport name with city and country name.

If it is the particular airport that you are trying to find then if you have the airport name (which you suggest you have in all cases shown) then there is only one airport that it can be, the city and country are irrelevant (assuming that airport name is unique). Therefore you just need where :name => airport_name

Colin

3

Thanks for your reply.

The thing is users may or may not know (or remember) the name of the airport they are looking for. So the search method needs to narrow down airports from the user inputs including city names and/or country names.

For example, you wish to travel from JFK New York USA (though it's a famous airport...), you don't clearly remember the name of the airport. All you can pull out from your memory is the country and the city, in this case 'New York' and 'USA'

You enter 'New York USA' in the form, the app narrows down the possibilities to the airport in 'New York (State) USA'. Once the list of possible airports is small, you now may be able to choose the name of the airport relatively easily.

I hope make myself clearer.

I am looking for something like

    scope :search_by_name, lambda { |name, city, country|         joins(:name).where("LOWER(name) LIKE ? AND LOWER(city) LIKE ? AND LOWER(country) LIKE ?", "%#{params[:name].downcase}%")     }

I have made this up, surely it won't work :slight_smile:

4

Thanks for your help.

I would like to raise another question related to this but different in a new thread.

soichi