Mongoose/MongoDB : How to update item which is nested 4 levels down? - node.js

Question

In my mongo database I have a tree like this:
-shopping-lists
|- list
|-products
|-item
|-item
|- list
|-products
|-item
|-item
I need to find which shopping list I'm updating and then go to products array, find an item inside and update one property.
I'm trying to solve this from few hours right now, but didn't find any solution.
How to update item which is nested 4 levels down??

Answer 1

After 6 hours of investigation, I have found an answer.
For any of you guys, having the same problem here is the answer.
While adding a new item to the Parent model, I've been just pushing these items as plain objects and the Parent model was like this:
const Parent = new Schema(
{
description: { type: String },
childrenArray: [Object],
},
{ timestamps: { createdAt: 'created_at' }, collection: 'shopping-lists' }
);
The problem was in childrenArray, that in the model I had declared this an array of objects.
Changing this to ChildrenModel solved the problem, cause now these items are saved as mongoose subdocuments and I can operate on then using $ operator.
new Schema looks like this:
const Children = new Schema(
{
prop1: { type: String, required: true },
prop2: { type: String, required: true },
prop3: { type: String },
},
{ timestamps: { createdAt: 'createdAt' } }
);
const Parent = new Schema(
{
description: { type: String },
products: [ItemSchema],
},
{ timestamps: { createdAt: 'created_at' }, collection: 'shopping-lists' }
);
Now I can easily access subdocuments like this:
const { name, isOrdered, author, voterIds, _id, listId } = req.body;
Parent.findOneAndUpdate(
{ _id: listId, 'children._id': _id },
{
$set: {
'children.$.isOrdered': true
}
},
(err, doc) => {
console.log(doc);
}
);

Answer 2

As far as i know We can update the nested document by positional operator that is $ but as according to the mongodb documentation we cannot update property nested more then 2 levels deep array. In simple you cannot use $ positional operator two times like "shoppinglists.$.list.$.products so its better to change the structure of your db to do it in better way