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1
2require 'bundler/setup'
3Bundler.require :default
4require 'veritas'
5require 'veritas/optimizer'
6require 'veritas-do-adapter'
7require 'virtus'
8require 'do_postgres'
9
10require 'dm-mapper'
11
12require 'debugger'
13
14url = "postgres://rails:rails@localhost:5432/ar_dm2"
15
16DataMapper.setup(:postgres, url)
17DataObjects.logger.set_log('do.log', :debug)
18connection = DataObjects::Connection.new(url)
19
20connection.create_command(<<-SQL).execute_non_query
21DROP TABLE IF EXISTS "public"."users";
22DROP SEQUENCE IF EXISTS "users_id_seq";
23
24CREATE SEQUENCE "users_id_seq" INCREMENT 1 START 1 MAXVALUE 9223372036854775807 MINVALUE 1 CACHE 1;
25ALTER TABLE "users_id_seq" OWNER TO "rails";
26
27CREATE TABLE "public"."users" (
28	"id" int4 NOT NULL DEFAULT  nextval('users_id_seq'::regclass),
29	"name" varchar(255) NOT NULL
30)
31WITH (OIDS=FALSE);
32ALTER TABLE "public"."users" OWNER TO "rails";
33
34insert into "public"."users" ( "name") values ( 'octocat');
35insert into "public"."users" ( "name") values ( 'dhh');
36SQL
37
38  class User
39    attr_accessor :likes, :id, :name
40
41    def initialize(attributes={})
42      @id = attributes[:id]
43      @name = attributes[:name]
44      @likes = attributes[:likes]
45    end
46  end
47
48  class Mapper < DataMapper::Mapper::VeritasMapper
49    map :id,   to: :id,   :type => Integer
50    map :name,   to: :name,   :type => String
51
52    model         User
53    relation_name :users
54    repository    :postgres
55  end
56
57
58  DataMapper.finalize
59
60  profiles_json   = [
61    {"profile"=>{"user_id"=>1, "likes"=>"meat, kats"}},
62    {"profile"=>{"user_id"=>2, "likes"=>"ruby, mac"}},
63    {"profile"=>{"user_id"=>3, "likes"=>"be invisible"}}
64  ]
65
66  profiles_header = [
67    [:user_id, Integer],
68    [:likes,   String ]
69  ]
70  profiles_tuple = profiles_json.map do |profile|
71    [ profile['profile']['user_id'], profile['profile']['likes']]
72  end
73  profiles_relation = Veritas::Relation::Base.new('profiles', profiles_header, profiles_tuple)
74
75
76  puts "Example from gist"
77
78  adapter = Veritas::Adapter::DataObjects.new(url)
79  users_header = [ [ :id, Integer ], [ :name, String ] ]
80
81  user_alt_relation = Veritas::Relation::Gateway.new(
82    adapter, Veritas::Relation::Base.new('users', users_header))
83
84  new_alt_relation = user_alt_relation.join(profiles_relation) do |r|
85    r.id.eq(r.user_id)
86  end
87
88  new_alt_relation.each do |user|
89    puts "User #{user[:id]} named #{user[:name]} likes #{user[:likes]}"
90  end
91
92  puts "Use Ruby object"
93
94  user_relation = DataMapper[User]
95
96  new_relation = user_relation.join(profiles_relation) do |r|
97    puts "Joining id=#{r.id} and user_id=#{r.user_id}"
98    r.id.eq(r.user_id)
99  end
100
101  new_relation.each do |user|
102    puts "User #{user.id} named #{user.name} likes #{user.likes}"
103  end