Mongoose update value in Array of Array in NodeJS - node.js

Question

my Test Schema:
var TestSchema = new Schema({
testName: String,
topic: {
topicTitle: String,
topicQuestion: [
{
questionTitle: String,
choice: [
{
name: String
age: Number
}
]
}
]
}
}, { collection: 'test' });
var Test = mongoose.model('test', TestSchema);
I want to update one age ($inc)value which I have the choice id.
I can have test id, topicQuestion id and choice id.
How to write this query in mongoose in NodeJS?
Normally I use the below query to update a value:
Test.findOneAndUpdate({ _id: testId }, { $inc: { ... } }, function (err, response) {
...
});
but it is so difficult to get in array and one more array. Thanks

Answer 1

You can use the $[] positional operator to update nested arrays.
router.put("/tests/:testId/:topicQuestionId/:choiceId", async (req, res) => {
const { testId, topicQuestionId, choiceId } = req.params;
const result = await Test.findByIdAndUpdate(
testId,
{
$inc: {
"topic.topicQuestion.$[i].choice.$[j].age": 1
}
},
{
arrayFilters: [{ "i._id": topicQuestionId }, { "j._id": choiceId }],
new: true
}
);
res.send(result);
});
Let's say we have this existing document:
{
"_id" : ObjectId("5e53e7d9bf65ac4f5cbf2116"),
"testName" : "Test 1",
"topic" : {
"topicTitle" : "Title",
"topicQuestion" : [
{
"_id" : ObjectId("5e53e7d9bf65ac4f5cbf211a"),
"questionTitle" : "Question 1 Title",
"choice" : [
{
"_id" : ObjectId("5e53e7d9bf65ac4f5cbf211c"),
"name" : "A",
"age" : 1
},
{
"_id" : ObjectId("5e53e7d9bf65ac4f5cbf211b"),
"name" : "B",
"age" : 2
}
]
},
{
"_id" : ObjectId("5e53e7d9bf65ac4f5cbf2117"),
"questionTitle" : "Question 2 Title",
"choice" : [
{
"_id" : ObjectId("5e53e7d9bf65ac4f5cbf2119"),
"name" : "C",
"age" : 3
},
{
"_id" : ObjectId("5e53e7d9bf65ac4f5cbf2118"),
"name" : "D",
"age" : 4
}
]
}
]
},
"__v" : 0
}
If we want to increment age value of a given choice, we send a PUT request using endpoint like this http://.../tests/5e53e7d9bf65ac4f5cbf2116/5e53e7d9bf65ac4f5cbf211a/5e53e7d9bf65ac4f5cbf211b where
"testId": "5e53e7d9bf65ac4f5cbf2116"
"topicQuestionId": "5e53e7d9bf65ac4f5cbf211a"
"choiceId": "5e53e7d9bf65ac4f5cbf211b"

Answer 2

You need to inform what choice you want and, on the update section, you need change the way you do increment.
Example:
Test.findOneAndUpdate({ _id: testId, topicQuestion.choice._id: choiceId}, { 'topicQuestion.$.choice': {$inc: { age: <numberToIncrement> }}}, {new: true}, function (err, response) {
...
});