My Mongo schema looks like this,
I want to update a flashcard object located in an array of flashcard also located in an array of subject.
const classrooms = new mongoose.Schema({
name: String,
year: String,
student: [
{
firstname: String,
lastname: String,
mail: String,
userId: String,
}
],
subject: [
{
subjectId: String,
flashcard: [
{
title: String,
tag: []
}
]
}
]
});
What I am doing is
const flashcard = await classroomModel.findOneAndUpdate({
_id : classroomId,
"subject" : {
"subjectId" : subjectId,
"subject.flashcard" : {
"_id" : flashcardId
}
},
"$set" : {
"flashcard.title" : "new title"
}
})
But this is deleting all flashcards located inside an object. Any help would be appreciated.
You need arrayFilters to specify the (to-be-updated) flashcard document that meets the criteria for subject and flashcard.
db.collection.update({
_id: 1//classroomId,
},
{
"$set": {
"subject.$[subject].flashcard.$[flashcard].title": "new title"
}
},
{
arrayFilters: [
{
"subject.subjectId": 1//subjectId
},
{
"flashcard._id": 1//flashcardId
}
]
})
Although i accepted @yong shun which is the best approach, another way to do it in case you don't like mongoose syntax :
const classroom = await classroomModel.findOne(
{
_id: 1 //classroomId,
},
)
const subject = classroom.subject.find(
(currentSubject: any) => {
return currentSubject.subjectId == 1 //subjectId
}
)
const flashcard = subject.flashcard.find(
(currentFlashcard: any) => {
return currentFlashcard._id == 1 //flashcardId
}
)
flashcard.title = "my new title";
await classroomModel.updateOne(classroom);