MongoDB/猫鼬在两个模型之间建立关系？

Question

我希望按照这个模式http://docs.mongodb.org/manual/tutorial/model-referenced-one-to-many-relationships-between-documents/创建一对多的关系。

我有一个Exercise.js模式，它将包含一组练习。

var exerciseSchema = new mongoose.Schema({

  _id: String,
  title: String,
  description: String,
  video: String,
  sets: Number,
  reps: String, 
  rest: Number

});

然后我就有了一个锻炼计划BeginnerWorkout.js模式

var workoutDaySchema = new mongoose.Schema({

  _id: String,
  day: Number,
  type: String,
  exercises: Array

});

我想将一系列的练习与workoutDaySchema联系起来，这包含了一组特定锻炼的锻炼天数，每天都有一组练习。

我有一个播种机功能，为我产生锻炼。

check: function() {

    // builds exercises
    Exercise.find({}, function(err, exercises) {
        if(exercises.length === 0) {
            console.log('there are no beginner exercises, seeding...');
            var newExercise = new Exercise({
                _id: 'dumbbell_bench_press',
                title: 'Dumbbell Bench Press',
                description: 'null',
                video: 'null',
                sets: 3, // needs to be a part of the workout day!!
                reps: '12,10,8', 
                rest: 1
            });
            newExercise.save(function(err, exercises) {
                console.log('successfully inserted new workout exercises: ' + exercises._id);
            });
        } else {
            console.log('found ' + exercises.length + ' existing beginner workout exercises!');
        }
    });


    // builds a beginner workout plan
    BeginnerWorkout.find({}, function(err, days) {
        if(days.length === 0) {
            console.log('there are no beginner workous, seeding...');
            var newDay = new BeginnerWorkout({
                day: 1,
                type: 'Full Body',
                exercises: ['dumbbell_bench_press'] // here I want to pass a collection of exercises.
            });
            newDay.save(function(err, day) {
                console.log('successfully inserted new workout day: ' + day._id);
            });
        } else {
            console.log('found ' + days.length + ' existing beginner workout days!');
        }
    });

}

因此，我的问题是在建立一个锻炼计划，我如何能够关联到exercises键使用猫鼬演习？

Answer 1

试试这个：

exercises: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Exercise', required: false }]

并使用exercise._id将练习添加到锻炼中(在上面的代码中，您需要将其放在相关的回调中，例如练习中的.save回调)：

newDay.exercises.push(newExercise._id);

_id通常是一个生成的数字，所以我不知道您是否可以将它设置为您建议的文本字符串。

当你进行.find()锻炼时，你也需要填充这些练习。类似于：

BeginnerWorkout.find({}).
    .populate('exercises')
    .exec(function(err, exercises) {
    //etc