How do I add a subdocument's data to a parent document (using mongoose)? - mongodb

Question

I am creating a MERN app and have a series of mongoose schema that are connected.
The hierarchy goes: Program -> Workout -> Exercise -> Set
Here is the model code for each Schema:
Program Schema
const programSchema = mongoose.Schema({
program_name:{
type: String,
},
workouts:[{
type: mongoose.Types.ObjectId,
ref: 'Workout'
}]
Workout Schema
const workoutSchema = mongoose.Schema({
workout_name:{
type:String
},
exercises: [{
type: mongoose.Types.ObjectId,
ref: 'Exercise'
}]
Exercise Schema
const exerciseSchema = mongoose.Schema({
exercise_name:{
type:String
},
notes:{
type:String
},
sets:[{
type: mongoose.Types.ObjectId,
ref: 'Set'
}]
Set Schema
const setSchema = mongoose.Schema({
weight:{
type: String
},
repetitions:{
type: String
},
rpe:{
type: String
}
My question is, now that they are all separate. How do I link a specific Set to a Exercise? or a specific Exercise to a Workout? etc. How do I reference them to each other so that I can create a whole program with various workouts, and each workout having various exercises, etc.
I would appreciate any wisdom. Thank you
For more info, here are the controllers.
Program Controller (CREATE NEW PROGRAM)
const createProgram = async (req, res) => {
//const {program_name, workouts} = req.body
try {
const program = new Program(req.body) // create a new program with the information requested
await program.save() // save it to database
res.status(201).send(program) // send it back to user
} catch (e) {
res.status(500).send(e)
}
WORKOUT CONTROLLER (CREATE NEW WORKOUT)
const createWorkout = async (req, res) => {
const {workout_name} = req.body
try {
const workout = await new Workout({
workout_name
})
await workout.save()
res.status(201).send(workout)
} catch(e) {
}
EXERCISE CONTROLLER (CREATE NEW EXERCISE)
const createExercise = async (req, res) => {
const { exercise_name='', notes='', sets } = req.body
try {
const exercise = await new Exercise({
exercise_name,
notes,
sets
})
await exercise.save()
res.status(201).send(exercise)
} catch (e) {
console.log(e)
}
SET CONTROLLER (CREATE NEW SET)
const createSet = async (req, res) => {
const {repetitions='', weight='', rpe=''} = req.body
try {
const set = await new Set({
weight,
repetitions,
rpe
})
await set.save()
res.status(201).send(set)
} catch (e) {
res.status(500).send(e)
}

Answer 1

The way I do it is on save I add the id to the attributed array. So i'll give you an example for one of your Routers then hopefully you can understand enough to do the rest.
For workouts you want to add it to a program when it's created. so when you create it, just add the id to the program you want to add it to.
Like so:
const {workout_name} = req.body
try {
const newWorkout = await Workout.create({
workout_name
})
Program.updateOne(
{ _id: req.params.ProgramId },
{ $addToSet: { workouts: newWorkout._id }},
)
res.status(201).send(workout)
} catch(e) {
}
So basically after creating your workout, you add that workout ID to the workouts array of the parent object. You would do the same for the rest of your Routers.