【Rails】 enumチュートリアル

1
2
# 定義
enum blood_type: { A: 0, B: 1, O: 2, AB: 3 }

1
2
3
4
5
6
7
# 複数個の定数リスト
User.blood_types
=> {"A"=>0, "B"=>1, "O"=>2, "AB"=>3}

# Userインスタンスのenumカラムの定数を表示
User.find_by(blood_type: 'A').blood_type
=> "A"

1
2
3
4
5
6
7
8
9
10
class CreateUsers < ActiveRecord::Migration[5.2]
  def change
    create_table :users do |t|
      t.string     :name,           null: false, default: ""
      t.integer   :age,              null: false
      t.timestamps
      t.timestamps
    end
  end
end

1
2
3
4
5
6
7
8
9
10
11
12
class CreateUsers < ActiveRecord::Migration[5.2]
  def change
    create_table :users do |t|
      t.string     :name,           null: false, default: ""
      t.integer   :age,              null: false
      # 新しくenum用のinteger型のblood_typeカラムを追加
      t.integer   :blood_type, null: false, default: 0
      t.timestamps
      t.timestamps
    end
  end
end

1
2
3
4
5
6
7
8
9
10
11
12
13
class CreateUsers < ActiveRecord::Migration[5.2]
  def change
    create_table :users do |t|
      t.string     :name,           null: false, default: ""
      t.integer   :age,              null: false
      t.integer   :blood_type, null: false, default: 0
      # 新しくenum用のboolean型のis_marriedカラムを追加
      t.boolean      :is_married,   null: false, default: false
      t.timestamps
      t.timestamps
    end
  end
end

1
2
3
class User < ApplicationRecord
  enum blood_type: { A: 0, B: 1, O: 2, AB: 3 }
end

1
2
3
4
5
6
7
8
9
10
11
12
User.create(
  name: 'programan_mother',
  age: 58,
  # blood_typeに'O'を指定
  blood_type: 'O'
)

INSERT INTO `users` (
  `name`, `age`, `blood_type`, `created_at`, `updated_at`)
VALUES (
  'programan_mother', 58, 2, '2020-01-25 07:01:24', '2020-01-25 07:01:24'
)

1
2
3
4
5
6
7
8
9
10
11
12
13
user = User.find_by(name: "programan_mother")

=> #<User:0x007fa7232290f8
  id: 1,
  name: "programan_mother",
  age: 58,
  blood_type: "O",
  is_married: false,
  created_at: Sat, 25 Jan 2020 07:01:24 UTC +00:00,
  updated_at: Sat, 25 Jan 2020 07:01:24 UTC +00:00>

user.blood_type
=> "O"

1
2
User.create(name: 'unknown_blood_type_programan',age: 40, blood_type: '血液型不明')
ArgumentError: '血液型不明' is not a valid blood_type

1
2
3
4
5
6
7
class User < ApplicationRecord
  # シンボルで定義する場合
  enum blood_type: [ :A, :B, :O, :AB ]

  # 文字列で定義する場合
  enum blood_type: [ "A", "B", "O", "AB" ]
end

1
2
3
class User < ApplicationRecord
  enum blood_type: { A: 0, B: 1, O: 2, AB: 3 }
end

1
2
3
4
5
6
class User < ApplicationRecord
  # シンボルで定義する場合
  enum blood_type: [ :A, :B, :O, :AB ]
  # 文字列で定義する場合
  enum blood_type: [ "A", "B", "O", "AB" ]
end

1
2
3
4
class User < ApplicationRecord
  enum blood_type: { A: 0, B: 1, O: 2, AB: 3 }
  enum is_married: { single: false, married: true } # 追加
end

1
2
3
4
5
6
7
8
9
10
User.create(
  name: 'programan_bigsister',
  age: 22, 
  blood_type: 'B', 
  # enumで設定した定数を指定
  is_married: 'married'
)

INSERT INTO `users` (`name`, `age`, `blood_type`, `is_married`, `created_at`, `updated_at`) 
  VALUES ('programan_bigsister', 22, 1, TRUE, '2020-01-28 06:32:16', '2020-01-28 06:32:16')

1
2
3
4
5
6
7
8
9
10
User.find_by(name: 'programan_bigsister')

=> #<User:0x007f82b384ec38
  id: 3,
  name: "programan_bigsister",
  age: 22,
  blood_type: "B",
  is_married: true,
  created_at: Tue, 28 Jan 2020 06:32:16 UTC +00:00,
  updated_at: Tue, 28 Jan 2020 06:32:16 UTC +00:00>

1
2
3
User.find_by(name: 'programan_bigsister').update(is_married: false)

ActiveRecord::NotNullViolation: Mysql2::Error: Column 'is_married' cannot be null: UPDATE `users` SET `is_married` = NULL,

1
2
nil = '何もない'
SyntaxError: (irb):1: Can't assign to nil

1
2
3
4
5
6
7
8
9
10
11
12
13
class CreateUsers < ActiveRecord::Migration[5.2]
  def change
    create_table :users do |t|
      t.string     :name,           null: false, default: ""
      t.integer   :age,              null: false
      # blood_typeカラムを予約語のtypeカラムに変更
      t.integer   :type, null: false, default: 0
      t.boolean  :is_married,   null: false, default: false
      t.timestamps
      t.timestamps
    end
  end
end

1
2
3
User.create(name: '予約語type登録', age: 0, type: 'A')

ActiveRecord::SubclassNotFound: The single-table inheritance mechanism failed to locate the subclass: 'A'. This error is raised because the column 'type' is reserved for storing the class in case of inheritance. Please rename this column if you didn't intend it to be used for storing the inheritance class or overwrite User.inheritance_column to use another column for that information.

1
2
3
4
5
6
7
8
9
10
11
12
13
class CreateUsers < ActiveRecord::Migration[5.2]
  def change
    create_table :users do |t|
      t.string     :name,           null: false, default: ""
      t.integer   :age,              null: false
      # 予約語のtypeからblood_typeに変更
      t.integer   :blood_type, null: false, default: 0
      t.boolean  :is_married,   null: false, default: false
      t.timestamps
      t.timestamps
    end
  end
end

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
user = User.find_by(name: 'programan')
=> #<User:0x007f82b7b6fe40
  id: 1,
  name: "programan",
  age: 25,
  blood_type: "A",
  is_married: false,
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00,
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>

user.blood_type
=> "A"

user.A?
=> true
user.B?
=> false
user.O?
=> false
user.AB?
=> false

user.C?
NoMethodError: undefined method `C?' for #<User:0x007f82b7b6fe40>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
user = User.find_by(name: "programan_father")
=> #<User:0x007f82b384d838
  id: 2,
  name: "programan_father",
  age: 58,
  blood_type: "A",
  is_married: true,
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00,
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>

user.blood_type
=> "A"

user.B!
UPDATE `users` SET `blood_type` = 1, `updated_at` = '2020-01-29 03:41:33' WHERE `users`.`id` = 2
=> true

user.blood_type
=> "B"

user.A!
UPDATE `users` SET `blood_type` = 0, `updated_at` = '2020-01-29 03:42:40' WHERE `users`.`id` = 2
=> true

user.blood_type
=> "A"

user.C!
NoMethodError: undefined method `C?' for #<User:0x007f82b7b6fe40>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
a_type_users = User.A

SELECT `users`.* FROM `users` WHERE `users`.`blood_type` = 0

=> [#<User:0x007f82b50f12e0 
  id: 1, 
  name: "programan", 
  age: 25, 
  blood_type: "A", 
  is_married: false, 
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00, 
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>,

 #<User:0x007f82b50f11a0 
  id: 2,
  name: "programan_father",
  age: 58,
  blood_type: "A",
  is_married: true,
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00,
  updated_at: Wed, 29 Jan 2020 03:42:40 UTC +00:00>,

 #<User:0x007f82b50f1060 
  id: 6,
  name: "programan_bigbrother",
  age: 28, 
  blood_type: "A",
  is_married: true,
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00,
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>
]

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
b_type_users = User.B
=> [#<#<User:0x007f82b6217010
  id: 4, 
  name: "programan_bigsister", 
  age: 30, 
  blood_type: "B", 
  is_married: true, 
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00, 
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>
]

o_type_users = User.O
=> [#<User:0x007f82b3964de8
  id: 3,
  name: "programan_mother",
  age: 58,
  blood_type: "O",
  is_married: true,
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00,
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>,
 #<User:0x007f82b39640a0
  id: 7,
  name: "programan_brother",
  age: 22,
  blood_type: "O",
  is_married: true,
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00,
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>
]

ab_type_users = User.AB
=> [#<User:0x007f82b5120248
  id: 5,
  name: "programan_sister",
  age: 20,
  blood_type: "AB",
  is_married: false,
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00,
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>
]

User.C
NoMethodError: undefined method `C' for #<Class:0x007f82bb9eabc0>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
インスタンス.enumカラム名_before_type_cast # 公式

user = User.find_by(blood_type: 'A')
=> [#<User:0x007fc8203c2518
  id: 1, 
  name: "programan", 
  age: 25, 
  blood_type: "A", 
  is_married: false, 
  created_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00, 
  updated_at: Wed, 29 Jan 2020 01:44:45 UTC +00:00>
]

user.blood_type_before_type_cast # 例: enumカラムがblood_typeの時
=> 0

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
a_type_user = User.find_by(blood_type: 'A')
a_type_user.blood_type_before_type_cast
=> 0

b_type_user = User.find_by(blood_type: 'B')
b_type_user.blood_type_before_type_cast
=> 1

o_type_user = User.find_by(blood_type: 'O')
o_type_user.blood_type_before_type_cast
=> 2

ab_type_user = User.find_by(blood_type: 'AB')
ab_type_user.blood_type_before_type_cast
=> 3

1
2
3
class User < ApplicationRecord
  enum blood_type: { A: 0, B: 1, O: 2, AB: 3 }
end

1
2
User.blood_types
=> {"A"=>0, "B"=>1, "O"=>2, "AB"=>3}

1
2
3
4
5
6
7
#keyだけ欲しい場合
User.blood_types.keys
=> ["A", "B", "O", "AB"]

#valueだけ欲しい場合
User.blood_types.values
=> [0, 1, 2, 3]

1
2
3
4
5
6
$ git clone -b enum https://github.com/miyagit/programan_dojo.git
$ cd programan_dojo

# programan_dojoのディレクトリにいるか確認
$ pwd
/Users/pikawaka/programan_dojo

1
2
3
$ bundle install
Bundle complete! 22 Gemfile dependencies, 87 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.

1
2
# bundle installに失敗した人のみ実行してください。うまくいった人はこの部分は無視して進んでください。
$ rbenv install 2.4.1

1
2
$ ls ~/.rbenv/versions | grep 2.4.1
2.4.1

1
2
3
4
5
6
7
# programan_dojoのディレクトリにいるか確認
$ pwd
/Users/pikawaka/programan_dojo

# rubyのバージョンが2.4.1であるか確認
$ ruby -v
ruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-darwin16]

1
2
3
$ bundle install
Bundle complete! 22 Gemfile dependencies, 87 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.

1
2
$ rails db:create && rails db:migrate && rails db:seed
環境構築が完了しました。

1
2
3
4
5
6
7
8
9
10
$ rails s
=> Booting Puma
=> Rails 5.2.1.1 application starting in development
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.12.0 (ruby 2.4.1-p111), codename: Llamas in Pajamas
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop

1
2
3
4
class User < ApplicationRecord
  # enumを定義
  enum blood_type: { A: 0, B: 1, O: 2, AB: 3 }
end

1
<%= f.select :blood_type, User.blood_types.keys.map {|k| [k, k]}, {}, { class: 'form-control', style: 'margin-bottom: 15px;', data: {} } %>

1
2
3
4
5
6
7
# enumで登録してる血液型の配列を作成
User.blood_types.keys
=> ["A", "B", "O", "AB"]

# ↑の配列からmapメソッドで二次元配列を作成
User.blood_types.keys.map {|k| [k, k]}
=> [["A", "A"], ["B", "B"], ["O", "O"], ["AB", "AB"]]

1
<%= f.select :blood_type, User.blood_types.keys.map {|k| [k, k]}, {}, { class: 'form-control', style: 'margin-bottom: 15px;', data: {} } %>

1
2
3
4
<select class="form-control" style="margin-bottom: 15px;" name="user[blood_type]" id="user_blood_type"><option selected="selected" value="A">A</option>
<option value="B">B</option>
<option value="O">O</option>
<option value="AB">AB</option></select>

1
2
3
4
5
6
7
8
9
10
def create
  # ↓を追加
  binding.pry
  @user = User.new(user_params)
  if @user.save
    redirect_to root_path, notice: 'userを作成できました。'
  else
    render :new
  end
end

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
<div class='p-top'>
  <table border="1" class= 'p-top__introduce'>
    <tr>
    <th>名前</th>
    <th>年齢</th>
    <th>血液型</th>
    <th>婚姻関係？</th>
    <th>血液型占い結果</th> <%# このコードを追加する%>
    </tr>
    <% @users.each do |user| %>
      <tr>
      <td><%= user.name %></td>
      <td><%= "#{user.age}歳" %></td>
      <td><%= "#{user.blood_type}型" %></td>
      <td><%= user.is_married? ? '既婚' : '未婚' %></td>
      <td></td> <%# このコードを追加する%>
      </tr>
    <% end %>
  </table>
</div>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
<div class='p-top'>
  <table border="1" class= 'p-top__introduce'>
    <tr>
    <th>名前</th>
    <th>年齢</th>
    <th>血液型</th>
    <th>婚姻関係？</th>
    <th>血液型占い結果</th>
    </tr>
    <% @users.each do |user| %>
      <tr>
      <td><%= user.name %></td>
      <td><%= "#{user.age}歳" %></td>
      <td><%= "#{user.blood_type}型" %></td>
      <td><%= user.is_married? ? '既婚' : '未婚' %></td>
      <td>
      <%# 18~26行目を追加%>
       <% if user.A? %>
         ビリ
       <% elsif user.B? %>
         一位
       <% elsif user.O? %>
         二位
       <% elsif user.AB? %>
         三位
       <% end %>
      <%# 18~26行目を追加%>
     </td>
     </tr>
   <% end %>
  </table>
</div>

1
2
3
4
5
# 変更前
<td><%= "#{user.blood_type}型" %></td>

# 変更後
<td><%= select :blood_type, :name, options_for_select(User.blood_types.keys.map{|k| [k, k]}, selected: user.blood_type), {}, { class: 'js-blood_type form-control', data: { id: user.id } } %></td>

1
2
3
4
5
6
7
8
9
10
11
12
# 変更前Rails.application.routes.draw do
  root 'main#top'
  resources :users
end

# 変更後
Rails.application.routes.draw do
  root 'main#top'
  resources :users do
    resource :blood_type, only: :update, controller: 'users/blood_type'
  end
end

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
$(document).ready(function() {
  $('.js-blood_type').change(function() {
    var user_id = $(this).data('id');
    var blood_type = $(this).val();

    $.ajax({
      type: 'PATCH',
      url: '/users/' + user_id + '/blood_type',
      data: {
        user: {
          id: user_id,
          blood_type: blood_type
        }
      },
      dataType: 'json',
    })
    .done(function(data) {
      alert(data.user_name + 'さんの血液型を' + data.blood_type + '型に更新しました。');
    })
  });
});

1
2
3
4
5
6
data: {
  user: {
    id: user_id,
    blood_type: blood_type
  }
}

1
2
params
=> {"user"=><ActionController::Parameters {"id"=>"2", "blood_type"=>"B"}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
class Users::BloodTypeController < UsersController
  def update
    binding.pry
    @user = User.find(params[:user][:id])

    case params[:user][:blood_type]
    when 'A'
      @user.A!
    when 'B'
      @user.B!
    when 'O'
      @user.O!
    when 'AB'
      @user.AB!
    end

    respond_to do |format|
      format.json { render json: {user_name: @user.name, blood_type: @user.blood_type} }
    end
  end
end

1
2
3
4
5
.done(function(data) {
  // data.usernameに@user.nameが入っており、blood_typeに@user.blood_typeが入ってます。
  // data == {user_name: "programan_father", blood_type: "B"}
  alert(data.user_name + 'さんの血液型を' + data.blood_type + '型に更新しました。');
})

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
class Users::BloodTypeController < UsersController
  before_action :set_user, :update_blood_type, only: :update

  def update
    respond_to do |format|
      format.json { render json: {user_name: @user.name, blood_type: @user.blood_type} }
    end
  end

  private

  def set_user
    @user = User.find(params[:user][:id])
  end

  def update_blood_type
    case params[:user][:blood_type]
    when 'A'
      @user.A!
    when 'B'
      @user.B!
    when 'O'
      @user.O!
    when 'AB'
      @user.AB!
    end
  end
end

1
2
3
4
5
6
7
8
9
10
class MainController < ApplicationController
  def top
    @users = User.all
    # ５ 〜 ８行目を追加しましょう。
    @a_type_users = User.A
    @b_type_users = User.B
    @o_type_users = User.O
    @ab_type_users = User.AB
  end
end

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
<div class='p-top'>
  <p class='p-top__label'>ユーザー一覧</p>
  <table border="1" class= 'p-top__introduce'>
    <tr>
    <th>名前</th>
    <th>年齢</th>
    <th>血液型</th>
    <th>婚姻関係？</th>
    <th>血液型占い結果</th>
    </tr>
    <% @users.each do |user| %>
      <tr>
      <td><%= user.name %></td>
      <td><%= "#{user.age}歳" %></td>
      <td><%= select :blood_type, :name, options_for_select(User.blood_types.keys.map{|k| [k, k]}, selected: user.blood_type), {}, { class: 'js-blood_type form-control', data: { id: user.id } } %></td>
      <td><%= user.is_married? ? '既婚' : '未婚' %></td>
      <td>
       <% if user.A? %>
         ビリ
       <% elsif user.B? %>
         一位
       <% elsif user.O? %>
         二位
       <% elsif user.AB? %>
         三位
       <% end %>
     </td>
     </tr>
   <% end %>
  </table>
</div>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
<div class='p-top'>
  <p class='p-top__label'>ユーザー一覧</p>
  <table border="1" class= 'p-top__introduce'>
    <tr>
    <th>名前</th>
    <th>年齢</th>
    <th>血液型</th>
    <th>婚姻関係？</th>
    </tr>
    <% @users.each do |user| %>
      <tr>
      <td><%= user.name %></td>
      <td><%= "#{user.age}歳" %></td>
      <td><%= select :blood_type, :name, options_for_select(User.blood_types.keys.map{|k| [k, k]}, selected: user.blood_type), {}, { class: 'js-blood_type form-control', data: { id: user.id } } %></td>
      <td><%= user.is_married? ? '既婚' : '未婚' %></td>
     </tr>
   <% end %>
  </table>
</div>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
<div class='p-top'>
  <p class='p-top__label'>ユーザー一覧</p>
  <table border="1" class= 'p-top__introduce'>
    <tr>
    <th>名前</th>
    <th>年齢</th>
    <th>血液型</th>
    <th>婚姻関係？</th>
    </tr>
    <% @users.each do |user| %> # each 〜 endまでを切り出す。
      <tr>
      <td><%= user.name %></td>
      <td><%= "#{user.age}歳" %></td>
      <td><%= select :blood_type, :name, options_for_select(User.blood_types.keys.map{|k| [k, k]}, selected: user.blood_type), {}, { class: 'js-blood_type form-control', data: { id: user.id } } %></td>
      <td><%= user.is_married? ? '既婚' : '未婚' %></td>
     </tr>
   <% end %>
  </table>
</div>

1
2
3
4
5
6
<tr>
<td><%= user.name %></td>
<td><%= "#{user.age}歳" %></td>
<td><%= select :blood_type, :name, options_for_select(User.blood_types.keys.map{|k| [k, k]}, selected: user.blood_type), {}, { class: 'js-blood_type form-control', data: { id: user.id } } %></td>
<td><%= user.is_married? ? '既婚' : '未婚' %></td>
</tr>

1
2
3
4
5
6
7
8
9
10
11
<div class='p-top'>
  <table border="1" class= 'p-top__introduce'>
    <tr>
    <th>名前</th>
    <th>年齢</th>
    <th>血液型</th>
    <th>婚姻関係？</th>
    </tr>
    <%= render partial: 'table_user', collection: @users, as: 'user' %>
  </table>
</div>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
<div class='p-top'>
  <p class='p-top__label'>ユーザー一覧</p>
  <table border="1" class= 'p-top__introduce'>
    <tr>
    <th>名前</th>
    <th>年齢</th>
    <th>血液型</th>
    <th>婚姻関係？</th>
    </tr>
    <%= render partial: 'table_user', collection: @users, as: 'user' %>
  </table>

  <div class='p-top__section'>
    <% User.blood_types.keys.each do |blood_type| %>
      <%= render 'blood_type_box', blood_type: blood_type %>
    <% end %>
  </div>
</div>

1
2
User.blood_types.keys
=> ["A", "B", "O", "AB"]

1
2
3
4
5
6
7
8
9
10
11
12
<div class='p-top__section__box'>
  <p class='p-top__section__box__label'><%= "#{blood_type}型一覧" %></p>
  <table border="1" class= 'p-top__section__box__table'>
    <tr>
    <th>名前</th>
    <th>年齢</th>
    <th>血液型</th>
    <th>婚姻関係？</th>
    </tr>
    <%= render partial: 'table_user', collection: blood_type_users(blood_type), as: 'user' %>
  </table>
</div>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
module ApplicationHelper
  def blood_type_users(blood_type)
    case blood_type
    when 'A'
      @a_type_users
    when 'B'
      @b_type_users
    when 'O'
      @o_type_users
    when 'AB'
      @ab_type_users
    end
  end
end

1
2
3
4
5
<div class='p-top__section'>
  <% User.blood_types.keys.each do |blood_type| %>
    <%= render 'blood_type_box', blood_type: blood_type %>
  <% end %>
</div>

1
2
3
4
5
6
7
8
9
10
11
12
13
class MainController < ApplicationController
  def top
    @users = User.all
    # 20歳~40歳のA型ユーザー一覧
    @a_type_users = User.A.where(age: 20..40)
    # 結婚しているB型ユーザー一覧
    @b_type_users = User.B.where(is_married: true)
    # 結婚していて50代のO型ユーザー一覧
    @o_type_users = User.O.where(age: 50..59).where(is_married: true)
    # 未婚で20代のAB型のユーザー一覧
    @ab_type_users = User.AB.where(age: 21..29).where(is_married: false)
  end
end

1
2
3
4
5
6
7
8
9
10
11
12
require_relative 'boot'
require 'rails/all'

Bundler.require(*Rails.groups)

module ProgramanDojo
  class Application < Rails::Application
    config.load_defaults 5.2
    # 下記を追加
    config.i18n.default_locale = :ja
  end
end

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
# 下記の4~16行目の記述をja.ymlの既に書かれているactiverecordとerrosの間に入れくてください。
ja:
  activerecord:
    models:
      user: ユーザー
    attributes:
      user:
        name: 名前
        age: 年齢
        blood_type: 血液型
        blood_types:
          A: A型
          B: B型
          O: O型
          AB: AB型
        is_married: 婚姻関係
    errors:

1
2
3
4
class User < ApplicationRecord
  enum blood_type: { A: 0, B: 1, O: 2, AB: 3 }
  validates :name, :age, :blood_type, presence: true
end

1
2
3
4
5
# 変更前
<%= f.select :blood_type, User.blood_types.keys.map {|k| [k, k]}, {}, { class: 'form-control', style: 'margin-bottom: 15px;', data: {} } %>

# 変更後
<%= f.select :blood_type, options_for_select(User.blood_types.map { |k, _v| [t("activerecord.attributes.user.blood_types.#{k}"), k] }), {include_blank: true}, { class: 'form-control', style: 'margin-bottom: 15px;', data: {} } %>

1
2
3
4
5
6
blood_types:
  # keyの部分がt("activerecord.attributes.user.blood_types.#{k}")のkに当たり、A型などに翻訳される。
  A: A型
  B: B型
  O: O型
  AB: AB型

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '2.4.1'

gem 'rails', '~> 5.2.0'
gem 'mysql2', '>= 0.3.18', '< 0.5'
gem 'puma', '~> 3.11'
gem 'sass-rails', '~> 5.0'
gem 'uglifier', '>= 1.3.0'
gem 'pry-rails'
gem 'coffee-rails', '~> 4.2'
gem 'turbolinks', '~> 5'
gem 'jbuilder', '~> 2.5'
gem 'bootsnap', '>= 1.1.0', require: false
gem 'bootstrap', '~> 4.1.1'
gem 'jquery-rails'
gem 'jquery-turbolinks'
# enum_helpを追加
gem 'enum_help'
...

1
2
3
4
5
6
7
8
9
ja:
  # 3行目から9行目を追加しましょう。
  enums:
    user:
      blood_type:
        A: A型
        B: B型
        O: O型
        AB: AB型

1
2
3
4
5
6
7
8
9
10
11
12
user = User.find_by(name: 'programan')
=> #<User:0x007f9ab7e01358
  id: 1,
  name: "programan",
  age: 25,
  blood_type: "A",
  is_married: false,
  created_at: Thu, 30 Jan 2020 06:55:05 UTC +00:00,
  updated_at: Fri, 31 Jan 2020 04:48:28 UTC +00:00>

I18n.t("activerecord.attributes.user.blood_types.#{user.blood_type}")
=> "A型"

1
2
3
4
5
6
7
8
9
10
11
12
user = User.find_by(name: 'programan')
=> #<User:0x007f9ab7e01358
  id: 1,
  name: "programan",
  age: 25,
  blood_type: "A",
  is_married: false,
  created_at: Thu, 30 Jan 2020 06:55:05 UTC +00:00,
  updated_at: Fri, 31 Jan 2020 04:48:28 UTC +00:00>

user.blood_type_i18n
=> "A型"

1
2
3
4
5
6
7
8
9
10
# enum_helpを使わずに書いた場合
User.blood_types.map { |k, _v| [I18n.t("activerecord.attributes.user.blood_types.#{k}"), k] }.to_h
=> {"A型"=>"A", "B型"=>"B", "O型"=>"O", "AB型"=>"AB"}

# enum_helpを使って書いた場合
User.blood_types_i18n.invert
=> {"A型"=>"A", "B型"=>"B", "O型"=>"O", "AB型"=>"AB"}

User.blood_types.map { |k, _v| [I18n.t("activerecord.attributes.user.blood_types.#{k}"), k] }.to_h == User.blood_types_i18n.invert
=> true

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
User.A

SELECT "users".* FROM "users" WHERE "users"."blood_type" = ?  [["blood_type", 0]]

=> [#<User:0x00007ff37a4c0868
  id: 1,
  name: "programan",
  age: 25,
  blood_type: "A",
  is_married: false>,
  #<User:0x00007ff37a4c07a0
  id: 2,
  name: "programan_father",
  age: 58,
  blood_type: "A",
  is_married: true>,
 #<User:0x00007ff37a4c06d8
  id: 6,
  name: "programan_bigbrother",
  age: 28,
  blood_type: "A",
  is_married: true>
]

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
User.not_A

SELECT "users".* FROM "users" WHERE "users"."blood_type" != ?  [["blood_type", 0]]

=> [#<User:0x00007ff37dc31018
  id: 3,
  name: "programan_mother",
  age: 58,
  blood_type: "O",
  is_married: true>,
 #<User:0x00007ff37dc30eb0
  id: 4,
  name: "programan_bigsister",
  age: 30,
  blood_type: "B",
  is_married: true>,
 #<User:0x00007ff37dc30d70
  id: 5,
  name: "programan_sister",
  age: 20, blood_type: "AB",
  is_married: false>,
 #<User:0x00007ff37dc30c08
  id: 7,
  name: "programan_brother",
  age: 22,
  blood_type: "O",
  is_married: true>,
  #<User:0x00007ff37dc309d8
  id: 8,
  name: "血液型B型一郎",
  age: 40,
  blood_type: "B",
  is_married: false>,
  #<User:0x00007ff37dc30898
  id: 9,
  name: "AB型二郎",
  age: 29,
  blood_type: "AB",
  is_married: false>
]

1
2
User.not_A
NoMethodError: undefined method `not_A' for #<Class:0x007fa8f556dec0>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
User.where.not(blood_type: 'A')
=> [#<User:0x00007ff37dc31018
  id: 3,
  name: "programan_mother",
  age: 58,
  blood_type: "O",
  is_married: true>,
 #<User:0x00007ff37dc30eb0
  id: 4,
  name: "programan_bigsister",
  age: 30,
  blood_type: "B",
  is_married: true>,
 #<User:0x00007ff37dc30d70
  id: 5,
  name: "programan_sister",
  age: 20, blood_type: "AB",
  is_married: false>,
 #<User:0x00007ff37dc30c08
  id: 7,
  name: "programan_brother",
  age: 22,
  blood_type: "O",
  is_married: true>,
  #<User:0x00007ff37dc309d8
  id: 8,
  name: "血液型B型一郎",
  age: 40,
  blood_type: "B",
  is_married: false>,
  #<User:0x00007ff37dc30898
  id: 9,
  name: "AB型二郎",
  age: 29,
  blood_type: "AB",
  is_married: false>
]

1
2
3
4
5
# rails5の場合
User.where.not(blood_type: 'A')

# rails6の場合
User.not_A