Update data in mongo db with condition of another collection - mongodb

Question

I have 2 collection in mongodb: Account, Information.
Account:
{
"_id": {
"$oid": "6348dc197a7b552660170d8b"
},
"username": "12345",
"password": "123dsgfdsgdfsg",
"email": "1243",
"role": "123",
"_infoid": {
"$oid": "6348dc197a7b552660170d8a"
}
}
Information:
{
"_id": {
"$oid": "6348dc197a7b552660170d8a"
},
"avatar": "hello",
"name": "Abcd",
"phonenumber": "012345678",
"address": "abcd"
}
I wanna change "phonenumber" to "123" but I just have "_id" of Account. Can I change it with aggregation pipeline?

Answer 1

Does this seem what you try to achieve?
// populate database with test data
use("test_db")
db.account.insertOne({
"_id": "6348dc197a7b552660170d8b",
"username": "12345",
"password": "123dsgfdsgdfsg",
"email": "1243",
"role": "123",
"_infoid": "6348dc197a7b552660170d8a"
})
db.information.insertOne({
"_id": "6348dc197a7b552660170d8a",
"avatar": "hello",
"name": "Abcd",
"phonenumber": "012345678",
"address": "abcd"
})
// define some test variables to use
let some_account_id = "6348dc197a7b552660170d8b"
let new_phone_number = "[phone]"
// change data
db.account.aggregate([
{
$match: {_id: some_account_id}
},
{
$addFields: {phonenumber: new_phone_number}
},
{
$project: {phonenumber: 1, _id: "$_infoid"}
},
{
$merge:{
into: "information",
whenNotMatched: "fail",
}
}
])
// show final results
db.information.find()
Result:
[
{
"_id": "6348dc197a7b552660170d8a",
"avatar": "hello",
"name": "Abcd",
"phonenumber": "[phone]",
"address": "abcd"
}
]

Answer 2

You don't need to duplicate _id, findOneAndUpdate() can be executed for this use case.
The definition of it is:
db.collection.findOneAndUpdate( filter, update, options )
which updates a single document based on the filter and sort criteria.
Below you can refer to the link for more details:
https://www.mongodb.com/docs/manual/reference/method/db.collection.findOneAndUpdate/
.

Answer 3

Performa a $lookup and perform some wrangling to your desired format. Finally do a $merge to update to the collection Information
db.Information.aggregate([
{
"$lookup": {
"from": "Account",
"localField": "_id",
"foreignField": "_infoid",
"pipeline": [
{
"$project": {
role: 1
}
}
],
"as": "AccountLookup"
}
},
{
"$unwind": "$AccountLookup"
},
{
$set: {
phonenumber: "$AccountLookup.role"
}
},
{
$unset: "AccountLookup"
},
{
"$merge": {
"into": "Information",
"on": "_id",
"whenMatched": "merge",
"whenNotMatched": "discard"
}
}
])
Here is the Mongo Playground for your reference.