MongoDB update multiple items in an array of objects with corresponding data - node.js

Question

I have an array in my MongoDB document as shown below:
{
...otherDocFields,
groupID: "group-id",
users: [
{id: "uid1", name: "User1"},
{id: "uid2", name: "User2"},
{id: "uid3", name: "User3"},
{id: "uid4", name: "User4"}
]
}
I'm trying to write a function that will update users' names based on that ID.
I tried something like:
async function updateNames(groupID: string, data: Array<{id: string, name: string}>) {
try {
// MongoDB Aggregation
await mongoDB.collection("users").aggregate([
{$match: {groupID}},
{$unwind: {
path: '$users',
includeArrayIndex: 'users.id',
preserveNullAndEmptyArrays: true
}
}
//....
])
} catch (e) {
console.log(e)
}
}
I'm stuck at the part to update the relevant names from the data param in the function.
A sample data would be:
[
{id: "uid1", name: "newName1"},
{id: "uid3", name: "newName3"}
]
I can for sure read, manually process it and update the document but I'm looking for a way to do it in single go using aggregation.

Answer 1

You can do this with an update statement using array filters (https://docs.mongodb.com/manual/reference/operator/update/positional-filtered/#---identifier--)
First, if we just declare some tests data which would be passed into your method:
const data = [
{id: "uid2", name: "ChangeName1"},
{id: "uid4", name: "ChangedName2"}
];
We can then create an update statement which updates all the users within that list within a map and a reduce:
const sets = data.map((element, index) => ({ [`users.$[f${index}].name`]: element.name })).reduce((accumulator, currentValue) => (Object.assign(currentValue, accumulator)), { });
const update = { $set: sets };
This will give us the following update statement:
{
"$set" : {
"users.$[f1].name" : "ChangedName2",
"users.$[f0].name" : "ChangeName1"
}
}
We can create a bunch of array filters with that data:
const arrayFilters = data.map((element, index) => ({ [`f${index}.id`]: element.id }));
This will give us the following which we can pass into the options of an update.
[ { "f0.id" : "uid2" }, { "f1.id" : "uid4" } ]
Last of all we can execute the following update command:
db.users.updateOne(
filter,
update,
{ arrayFilters }
);
Now if we check the output we'll get the following results
> db.users.find().pretty()
{
"_id" : ObjectId("60e20841351156603932c526"),
"groupID" : "123",
"users" : [
{
"id" : "uid1",
"name" : "User1"
},
{
"id" : "uid2",
"name" : "ChangeName1"
},
{
"id" : "uid3",
"name" : "User3"
},
{
"id" : "uid4",
"name" : "ChangedName2"
}
]
}