Question

在我的MechanicsController中，创建操作有效，但是，当我检查数据库时，我注意到出租车永远不会得到一个driver_id，我似乎永远无法让出租车包含一个mechanic_id和driver_id at在同一时间，我不知道我哪里出错了。

非常感谢帮助...

class Driver < ActiveRecord::Base
  has_many :taxis
  has_many :mechanics, :through => :taxis
end


class Mechanic < ActiveRecord::Base
  has_many :driver, :through => :taxis
  has_many :taxis
end


class Taxi < ActiveRecord::Base
  belongs_to    :driver
  belongs_to :mechanic
end

class MechanicsController < ApplicationController
  def create

    this_driver=Driver.find(params[:driver_id])
    @mechanic = this_driver.mechanics.new(params[:mechanic])
    @taxi=@mechanic.taxis.new(params[:queueprocessor])

    respond_to do |format|
      if @mechanic.save
        format.html { redirect_to @mechanic, notice: 'Mechanic was successfully created.' }
        format.json { render json: @mechanic, status: :created, location: @mechanic }
      else
        format.html { render action: "new" }
        format.json { render json: @mechanic.errors, status: :unprocessable_entity }
      end
    end
  end
end

以下是我的迁移：

class CreateDrivers < ActiveRecord::Migration
  def change
    create_table :drivers do |t|
      t.timestamps
    end
  end
end


class CreateMechanics < ActiveRecord::Migration
  def change
    create_table :mechanics do |t|
      t.timestamps
    end
  end
end

class Taxis < ActiveRecord::Migration
  def change
    create_table :taxis do |t|
      t.belongs_to :driver
      t.belongs_to :mechanic
      t.timestamps
    end
  end
end

谢谢

Answer 1

这里有一些问题。改变这个：

class Mechanic < ActiveRecord::Base
  has_many :driver, :through => :taxis
  has_many :taxis
end

到此（请注意，:driver已更改为:drivers）：

class Mechanic < ActiveRecord::Base
  has_many :taxis
  has_many :drivers, :through => :taxis
end

此外，在create操作中，您将按错误的顺序附加模型：

this_driver=Driver.find(params[:driver_id])
# this_driver.mechanics can't create a new association without a Taxi join model
@mechanic = this_driver.mechanics.new(params[:mechanic])   
@taxi=@mechanic.taxis.new(params[:queueprocessor])

应改为：

this_driver=Driver.find(params[:driver_id])
@taxi = this_driver.taxis.build(params[:queueprocessor])
@mechanic = @taxi.build_mechanic(params[:mechanic])

Answer 2

变化：

has_many :driver, :through => :taxis

为：

has_many :drivers, :through => :taxis

rails has_many通过并在控制器中调用关联

2 个答案: