Update nested array objects in MongoDB - node.js

Question

I have to deal with objects of the following type in a NodeJS app (using mongodb driver):
data_test = {
"id": "105-20090412",
"date": new Date('2020-09-04T14:00:00.000Z'),
"station": {
"name": "AQ105",
"loc": {
"type": "Point",
"coordinates": [14.324498, 40.821930]
},
"properties": {}
},
"samples": [{
"t": new Date('2020-09-04T14:14:00.000Z'),
"data": {
//"temp_celsius": 31.81,
//"humRelPercent": 39,
"press_mBar": 1021.12,
"PM10": 200
}
}]
}
I receive every 2 minutes data as above.
I want to:
If the data received has an id not yet present on MongoDB do an insert
If the data received has a sample object with a Date (t property) yet present then add properties to this one (for example readings of different sensors)
If the data received has a sample object with a Date (t property) not yet present in samples array, then add this new one
I would like to do what described above with the minor count possible of round-trips to the MongoDB server.
I hope to have been clear enough.
Any suggestion?
Thanks in advance.

Answer 1

Here's my suggestion, this is not the correct answer. You will need to fiddle with the query portion. The query below should work for 1 & 3, for 2 you will have to play around.
db.collection.updateOne(
{ "id" : "105-20090412", "samples.t": <Date> },
{ $push: { "samples" : <sample> } },
{ $setOnInsert: { station: <station> } },
{ upsert: true }
);
References:
https://docs.mongodb.com/manual/reference/method/db.collection.updateOne/
https://docs.mongodb.com/manual/reference/operator/update/setOnInsert/#up._S_setOnInsert
https://docs.mongodb.com/manual/reference/operator/update/push/

Answer 2

I finally came to the following solution, perhaps not the most efficient one:
try {
const db = client.db(dbName);
const collection = db.collection(collectionName);
// retrive id, station, date and samplesToAdd as separate objects
let {
id,
...dataToInsert
} = data
//id = new ObjectID(id)
const queryBy_id = {
_id: id
}
// first check if doc exists
let res_query = await collection.findOne(queryBy_id)
// if doc does not exists then insert a new one
if (!res_query) {
res_insert = await collection.insertOne({
_id: id,
...dataToInsert
})
return res_insert;
} else {
// retrive samples from initial query
let current_samples = res_query.samples
// check if sample in dataToInsert yet exists
// use getTime to correctly compare dates
let idx = current_samples.findIndex(x => x.t.getTime() == dataToInsert.samples[0].t.getTime())
if (idx >= 0) {
// find index of sample to update
let current_t = current_samples[idx].t
// merge data yet stored with new one
current_samples.data = {
...current_samples[idx].data,
...dataToInsert.samples[0].data
}
let resUpdateSample = await collection.updateOne({
_id: id,
'samples.t': current_t
}, {
$set: {
'samples.$.data': current_samples.data
}
})
return resUpdateSample
} else {
// add data to samples array
let resAddToSamples = await collection.updateOne({
_id: id
}, {
$push: {
samples: dataToInsert.samples[0]
}
})
return resAddToSamples
}
}
} catch (err) {
logger.error(err);
}
How can I improve it?
Thanks.