ruby - How to get data from other tables using Sequel -

i use sequel , have following 2 models in sinatra app

# foo.rb require 'sequel'  module notes   module models     class foo < sequel::model       plugin :json_serializer, naked: true       plugin :validation_helpers        one_to_many :bars        def validate         super          validates_presence [:foo_name], message: "can't empty"       end     end   end end   # bar.rb require 'sequel'  module notes   module models     class bar < sequel::model       plugin :json_serializer, naked: true       plugin :validation_helpers        many_to_one :foo        def validate         super          validates_presence [:bar_name], message: "can't empty"       end     end   end end 

there foo_id foreign key in bar table.

i have api route can bars or specific bar if parameter passed in, looks like:

app.get '/api/bars'   require_session   bar_name = params[:bar_name]   bar_model = models::bar    if bar_name.nil?     bar_model.all.to_json   else     bar_model.where(sequel.ilike(:bar_name, '%' + bar_name + '%'))       .all       .to_json   end end 

what i'd haven't figured out yet how can @ least foo_name foo table in result well, retrieved based on foo_id that's in bar table?

even more, if there longer association, there's foreign key, example baz_id, in foo table that's linked baz table, , in same api, want info foo , baz tables based on foreign key association in respective tables.

hope makes sense , appreciated.

you can use :include option of sequel's to_json method this. can specify in model when set json_serializer options, can override defaults when call to_json on instance.

so, on individual instance of bar, do:

bar.first.to_json(include: {foo: {only: :foo_name}}) 

if want full list, in example, want call on class. note if call on array won't work, must call on dataset before converting array.

# models  bar.to_json(include: {foo: {only: :foo_name}})  # subset of models bar.where(sequel.ilike(:bar_name, '%' + bar_name + '%'))   .to_json(include: {foo: {only: :foo_name}})