ruby-on-rails-4 – Ruby on Rails连接多个表以及如何提取数据

我正在尝试在 Ruby on Rails上为餐馆预订系统.我有三个表：用户,表和预订. ‘users’包含列’id’,’name’,’email’,’phone’和’totalPersons’. ‘table’有列’id’和’seat’. ‘reservations’包含列’id’,’user_id’,’table_id’和’begin_datetime’.

模型看起来像这样：

class User < ActiveRecord::Base
  has_many :reservations
  has_many :tables,:through => :reservations
end

class Table < ActiveRecord::Base
  has_many :reservations
  has_many :users,:through => :reservations
end

class Reservation < ActiveRecord::Base
  belongs_to :table
  belongs_to :user
end

我能够加入桌子和预订表,但我无法加入这三个.

我试图显示一个完整的预订名称和用户在什么表.

<table>
  <thead>
    <tr>
      <th>Reserverings ID</th>
      <th>Tafel nummer</th>
      <th>Seats</th>
      <th>User</th>
      <th>Begint om</th>      
      <th></th>
      <th></th>
      <th></th>
    </tr>
  </thead>
  <tbody>
    <% @tables.each do |table| %>
      <tr>
        <td><%= reservation.id %></td>
        <td><%= reservation.table_id %></td>
        <td><%= table.seats %></td>
        <td><%= user.name %></td>
        <td><%= reservation.begin_datetime %></td>
        <td><%= link_to 'Show',table %></td>
        <td><%= link_to 'Edit',edit_table_path(table) %></td>
        <td><%= link_to 'Destroy',table,method: :delete,data: { confirm: 'Are you sure?' } %></td>
      </tr>
    <% end %>
  </tbody>
</table>

在控制器中,我的连接看起来像

@reservations = reservation.joins(:tables,:users)

你能帮助我吗？
Rails版本4.0

编辑：
在http://guides.rubyonrails.org/我看到了

Post.joins(:comments => :guest)

生成的SQL是：

SELECT posts.* FROM posts
    INNER JOIN comments ON comments.post_id = posts.id
    INNER JOIN guests ON guests.comment_id = comments.id

我想我的SQL代码用于所有用户预订和他们预订的表格看起来像

SELECT * FROM reservations,users,tables
    INNER JOIN reservations ON reservations.user_id = users.id
    INNER JOIN reservations ON reservations.table_id = tables.id

也许这会为你澄清一些事情.所以现在我需要知道如何在轨道上的ruby中产生.

Reservation.joins('INNER JOIN "tables" ON "tables"."id" = "reservations"."table_id" INNER JOIN "users" ON "users"."id" = "reservations"."user_id"')

Reservation.joins(:user).joins(:table)

Reservation.joins(:user).joins(:table).select("tables.seats AS table_seats")