Question

“大家好”我现在正在练习一下rails，我遇到了解如何通过关联访问数据的问题。目前我有3个表，医生，患者和预约。

      class CreateDoctors < ActiveRecord::Migration
      def change
        create_table :doctors do |t|
          t.string :name

          t.timestamps null: false
        end
      end
    end

        class CreatePatients < ActiveRecord::Migration
      def change
        create_table :patients do |t|
          t.string :name

          t.timestamps null: false
        end
      end
    end

        class CreateAppointments < ActiveRecord::Migration
      def change
        create_table :appointments do |t|
          t.date :date_appointment
          t.references :doctor, index: true, foreign_key: true
          t.references :patient, index: true, foreign_key: true

          t.timestamps null: false
        end
      end
    end

有了这个，我正在尝试创建一个表格以在约会表上插入记录，这样我就可以在提交表格后访问并获取医生或患者的姓名。

    <%= form_for(@appointment) do |f| %>
 <%= f.label :date, "Choose a date for your appointment" %>
 <%= f.collection_select(:doctor_id, Doctor.all, :id, :name, prompt: true) %>
 <%= f.submit %>
<% end %>

正在插入数据，但是当我调用Show“Template”时，即使它有一个值，也会给我一个错误，说明“Nil”中的医生参数。

    <%= @appointment.doctor.name %>

这是预约控制器数据

        class AppointmentsController < ApplicationController

        def index
        end

        def show

        end

        def new
            @appointment = Appointment.new
        end

        def create
            @appointment = Appointment.new(appointment_params)
            if @appointment.save
                redirect_to @appointment
            else
                render "New"
            end
        end

        private

        def appointment_params
            params.require(:appointment).permit(:date, :doctor_id, :patient_id)
        end

        def find_appointment
            @appointment = Appointment.find(params[:id])
        end



        end

我想要做的是基本上能够根据在使用表单创建新行之后创建的行上的属性值来呈现或显示医生或患者的姓名。

class Appointment < ActiveRecord::Base
      belongs_to :doctor
      belongs_to :patient
    end

class Doctor < ActiveRecord::Base
    has_many :appointments
    has_many :patients, through: :appointments
end

class Patient < ActiveRecord::Base
    has_many :appointments
    has_many :doctors, through: :appointments
end

感谢您的时间！

Answer 1

也许我错过了一些东西，但是你没有忘记设置@appointment var？

 def show
   @appointment = Appointment.find(params['id'])
 end

（如果你有这样的路线应该有用）

如何使用关联访问其他表的属性

1 个答案: