How to set an ObjectId in Mongoose?

Question

I have a flights model file:

const flightsSchema = new Schema({
  departureDate: {
    type: String,
    required: true,
  },
  returnDate: {
    type: String,
  },
});

Then I have a trips model file:

const tripsSchema = new Schema({
  email: {
    type: String,
    required: true,
    lowercase: true,
    unique: true,
  },
  flight: {
    type: mongoose.Schema.Types.ObjectId,
    ref: Flights,
    required: true,
  },
});

Finally, I have an expressJS route that tries to create a new Trip:

  const testData = {
    email: "email123@gmail.com",
    flight: {
      departureDate: "today",
      returnDate: "tomorrow",
    },
  };
    
  const trip = new Trips(testData);
  try {
    await trip.save();
    return res.status(200).json({
      success: true,
    });
  } catch (err) {
    console.log(err);
  }
    });

However, when I visit the route, I get the following error:

Error: Argument passed in must be a single String of 12 bytes or a
 string of 24 hex characters
          at new ObjectID

Why is this error coming?

Answer 1

First create the Flight document and save it. Then save the _id of the Flight document in the Trip document.

const flightData = {
  departureDate: "today",
  returnDate: "tomorrow",
};

try {
  // Save flight data
  const flight = new Flights(flightData);
  const flightObject = await flight.save();

  // Save trip data
  const trip = new Trips({
    email: "email123@gmail.com",
    flight: flightObject._id
  });
  await trip.save();
  return res.status(200).json({
    success: true,
  });
} catch (err) {
  console.log(err);
}
});