Question

我的应用包含用户添加到锻炼中的练习。用户可以创建练习或选择现有练习。

***更新**** 我根据Ben的解决方案添加了一个模型。在尝试向锻炼添加锻炼时，我收到如下错误。我的语法错了吗？我尝试过像this这样的解决方法：

w=Workout.last
e=Exercise.last

w.exercises.build(:exercise => e)  # NameError: uninitialized constant Workout::ExercisesWorkout
w.exercises_workouts.create(:exericse_id => 1) #NameError: uninitialized constant Workout::ExercisesWorkout

我对协会附带的新方法以及“_”是否感到困惑，camelCase，Pluralize，symbol..etc。

Rails似乎在寻找班级ExercisesWorkout，但我定义了“exercise_workouts”和/或ExercisesWorkouts。

感谢。

我在使用rails控制台向锻炼添加练习时遇到了麻烦。我看到2个潜在的问题：

我不知道这样做的正确语法（构建，创建，查找）
正确设置应用程序（连接表，模型，等等）

请告诉我我的错误在哪里，以及是否有更好的结构/关联可供使用。

谢谢。

型号：

class Exercise < ActiveRecord::Base
    has_many :workouts, :through => :exercises_workouts
    has_many :exercises_workouts
end


class Workout < ActiveRecord::Base
    has_many :exercises, :through => :exercises_workouts
    has_many :exercises_workouts
end

class ExercisesWorkouts < ActiveRecord::Base
    belongs_to :exercise
    belongs_to :workout
end

schema.db：

ActiveRecord::Schema.define(version: 20141129181911) do

  # These are extensions that must be enabled in order to support this database
  enable_extension "plpgsql"

  create_table "exercises", force: true do |t|
    t.string   "name"
    t.string   "description"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "exercises_workouts", id: false, force: true do |t|
    t.integer "exercise_id", null: false
    t.integer "workout_id",  null: false
  end

  create_table "workouts", force: true do |t|
    t.string   "name"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

end

ERROR：

 w=Workout.new #create new workout
 w.name = 'test' #name workout
 w.save #save workout

 e1=Exercise.new #create new exercise
 e1.name='press' #name exercise
 e1.save #save exercise

#I'm not sure of the syntax here... I've tried alot between create, build using symbols and finds...., this is just one example.. 
 w.exercises.create(e1) #NameError: uninitialized constant Workout::ExercisesWorkout

Answer 1

您还需要连接表的模型：

class ExercisesWorkouts < ActiveRecord::Base
    belongs_to :exercise
    belongs_to :workout
end

如果您有兴趣，以下是更详细地介绍联接表的答案：

What would the joining table called in this case in Rails 3.1?

使用Rails时的错误has_many：通过关联

1 个答案: