ruby - How to implement Active Record like 'find' method in Sinatra and Sequel? -

i building simple sinatra app training purposes.

i using sequel gem , don't want use active record.

my files are:

/models/idea.rb:

class idea   attr_reader :id, :title, :description    def initialize(input)     @id = input[:id]     @title = input[:title]     @description = input[:description]   end    def save     idea.data.insert(title: title, description: description)   end    def self.create_table     database.create_table? :ideas       primary_key :id       string :title, size: 25       text :description     end   end    def self.data     verify_table_exists     database[:ideas]   end    def self.database     @database ||= sequel.sqlite('./db/idea_box.sqlite3')   end    def self.all     data.order(sequel.desc(:id)).collect |row|       idea.new(row)     end   end    def self.verify_table_exists     @table_exists ||= (create_table || true)   end    def self.find(params)     data.where(id: params)   end # tried this: # #  def self.find(params) #    data.where(id: params).collect |row| #      idea.new(row) #    end #  end    end end 

/views/edit.haml:

%h1 edit idea %form{action:"/#{@idea.id}", method: "post"}   %input{type: "hidden", name: "_method", value: "put"}   %input{type: "text", name: "idea_name", value: "#{@idea.title}"}   %br   %textarea{name: "idea_description", value: "#{@idea.description}"}   %br   %input{type: "submit", value: "submit"} 

application.rb:

require './models/idea'   bundler.require  helpers   def title     if @title       "#{@tile} -- ideabox"     else         "ideabox"     end   end    def delete_idea_button(idea_id)     haml :_delete_idea_button, locals: {idea_id: idea_id}   end end    '/'   @ideas = idea.all   haml :index end  not_found   haml :error end  post '/create'     idea = idea.new(title: params['idea_name'], description: params['idea_description'])   idea.save    redirect to('/') end  '/edit/:id'   @idea = idea.find(params[:id])   @title = "edit form"   haml :edit end  put ':id'   @idea = idea.find(params[:id])   @title = "edit form"   haml :edit end 

just find method work when use this:

def self.find(params)   record = data[id: params]   if record.nil?     nil     # or raise exception...   else     self.new(record)   end end 

but have reimplement features active record has, example kind of persisted? method check if record present in database , update record instead of creating new one.

with current implementation of save create new record each time call it. may better if don't set id let auto_increment of database handle that.