Is it possible to only populate certain fields MongoDB - angularjs

Question

I'm using the following model schema:
var AppointmentSchema = new Schema({
appointment_date: {type: Date},
created: {
type: Date,
default: Date.now
},
updated: {type: Date},
client: [{ type: Schema.Types.ObjectId, ref: 'User' }],
staff_id: [{ type: Schema.Types.ObjectId, ref: 'User' }],
cost:{
type: Number
},
jobDone:{
type: Boolean,
default: false
},
cancelled:{
type: Boolean,
default: false
}
});
Which clearly references the User model.
When I query I want to populate the client and staff data, but without some of the fields that they hold within that model.
So if the Users model is:
var UserSchema = new Schema({
firstName: {
type: String,
trim: true,
default: '',
validate: [validateLocalStrategyProperty, 'Please fill in your first name']
},
lastName: {
type: String,
trim: true,
default: '',
validate: [validateLocalStrategyProperty, 'Please fill in your last name']
},
displayName: {
type: String,
trim: true
}
});
I would only want to populate with firstName and email (and omit the rest) is that possible?

Answer 1

To return a few specific fields returned for the populated documents, you need to pass the usual field name syntax as the second argument to the populate method:
Appointment
.findOne({ cancelled: true })
.populate('client', 'firstName displayName') // only return the User's firstName and displayName
.exec(function (err, appointment) {
if (err) return handleError(err);
console.log('The client name is %s', appointment.client.firstName);
// prints "The client name is Aaron"
console.log('The client display name is %s', appointment.client.displayName);
// prints "The client display name is aarontest'
})