How to Join model in Mongodb(Mongoose) and express? - node.js

Question

I have 3 models 'User' , 'Doctor', 'Appointment', I want to let the user make an appointment then when he get his appointment I want to return the doctor name, also when the doctor get the appointment I want t return the user Name.
User Model :
const mongoose = require('mongoose');
const User = mongoose.Schema({
name: {
type: String,
required: true,
},
email: {
type: String,
required: true,
},
password: {
type: String,
required: true,
},
})
const User = mongoose.model('User', User);
module.exports = { User };
Doctor Model :
const mongoose = require('mongoose');
const Doctor = mongoose.Schema({
name: {
type: String,
required: true,
},
email: {
type: String,
required: true,
},
password: {
type: String,
required: true,
},
})
const Doctor = mongoose.model('Doctor', Doctor);
module.exports = { Doctor };
Appointment Model :
const mongoose = require('mongoose');
const Appointment = mongoose.Schema({
date: {
type: Date,
},
time: {
type: Date
},
_userID: {
type: mongoose.Types.ObjectId,
ref: 'User'
},
_doctorID: {
type: mongoose.Types.ObjectId,
ref: 'Doctor'
}
})
const Appoitment = mongoose.model('Appoitment', Appointment);
module.exports = { Appoitment };
Make and Get Appointment :
const express = require('express');
const { Appointment } = require('../DataBase/Models/appointment.model');
const router = express.Router();
router.get("/appointment/:id", async (req, res) => {
try {
const appointment = await Appointment.find({
user: req.params.id,
}).populate({
path: "doctor",
model: "Doctor",
});
res.send({
status: 200,
message: "SuccessFull",
Appointments: appointment,
});
} catch (error) {
res.send({
status: 400,
message: `Error: ${error}`,
});
}
});
router.post("/appointment", async (req, res) => {
try {
const makeAppointment = new Appointment(req.body);
const result = await makeAppointment.save();
res.send({
status: 200,
message: "SuccessFull",
Appointment: result,
});
} catch (error) {
res.send({
status: 404,
message: `Error : ${error}`,
});
}
});
My Question is How I can return the Appointment with the doctor Name the same with the User Name ??

Answer 1

in the .populate method, the path param is the name of the attribute in the model that you're trying to retrieve, so instead of path: 'doctor', you should be using '_doctorID' because you used this as the attribute name in the Appointment Model.
The same works for your query in the .find, you're querying the 'user' attribute, but you have _userID in your appointment model.
So, you have to 2 options:
Change _userID and _doctorID to user and doctor, this way should be better;
Or change user and doctor in your controller to _userID and _doctorID;
If you follow the first option, your code now should be something like:
Appointment Model:
const mongoose = require('mongoose');
const Appointment = mongoose.Schema({
date: {
type: Date,
},
time: {
type: Date
},
user: {
type: mongoose.Types.ObjectId,
ref: 'User'
},
doctor: {
type: mongoose.Types.ObjectId,
ref: 'Doctor'
}
})
const Appoitment = mongoose.model('Appoitment', Appointment);
module.exports = { Appoitment };
Appointment Controller:
router.get("/appointment/:id", async (req, res) => {
try {
const appointment = await Appointment.find({
user: req.params.id,
})
.populate({
path: "doctor",
select: "_id name",
});
res.send({
status: 200,
message: "SuccessFull",
Appointments: appointment,
});
} catch (error) {
res.send({
status: 400,
message: `Error: ${error}`,
});
}
});

Answer 2

if you want to select specific column .
it will look like .populate('author', 'name'). // only return the Author name