change fields of object inside array in mongoose

Question

my application tracking student enrollment to different courses.

the schema is:

const userSchema = new mongoose.Schema({
 username: String,
 password: Number,
 enrollment: []
})

and the enrollment array looks like this:

[{courseName: somename, courseTime:sometime},{courseName: somename2, courseTime:sometime2}]

the student can supply information whether he was attend at specific date on the course meeting or not.

so the thing I want to do is:

a) find the specific student b) find the the specific course of this student c) add to the object that contains this course additional object that contain date field and yes/no field.

so i wont it looks something like this:

[{courseName: somename, courseTime:sometime, newObject:{date:someDate, attendance:true}},{courseName: somename2, courseTime:sometime2,newObject:{date:someDate2, attendance:false}}]

I found similar questions in topics like this: update Object inside array of Object with mongoose or update Object inside array of Object with mongoose

and its not seems like a very hard task, but the problem is that I probably missing some simple syntax rules, because when I type this code into VScode I see picture like this:

error

any help would be much appreciated

Answer 1

Here's one way to update "enrollment" and add "newObject".

db.collection.update({
 "username": "john1234" // from req.body.username
},
{
 "$set": {
 "enrollment.$[course].newObject": {
 // from req.body.xxx
 "date": ISODate("2022年12月01日T09:00:00Z"),
 "attendance": true
 }
 }
},
{
 "arrayFilters": [
 { // from req.body.courseName
 "course.courseName": "NIE-SW101"
 }
 ]
})

Example output:

[
 {
 "_id": ObjectId("5a934e000102030405000000"),
 "enrollment": [
 {
 "courseName": "NIE-SW101",
 "courseTime": ISODate("2022年12月01日T09:00:00Z"),
 "newObject": {
 "attendance": true,
 "date": ISODate("2022年12月01日T09:00:00Z")
 }
 },
 {
 "courseName": "NIE-HI101",
 "courseTime": ISODate("2022年12月05日T15:00:00Z")
 }
 ],
 "password": 1234,
 "username": "john1234"
 }
]

Try it on mongoplayground.net.