Inserting data to nested array in mongodb - mongodb

Question

I have a document which looks like this
{
_id:1,
list_id:23,
name:'list01'
cards:[
{
id:3,
name:'card01'
categories:[{
id:10,
category:'section01',
tags:[{id:11,name:'tag01',is_selected: true}]
}]
}
]
}
I need to insert/push some data to tags array in a selected category for a given list_id but I'm getting an error saying
MongoError: Too many positional (i.e. '$') elements found in path
'cards.$.categories.$.tags'
This is the query that I have tried out. What's wrong with this query any idea on how to achieve this?
db.collection(TABLE)
.updateOne(
{ list_id: 23, 'cards.categories.category': 'section01'},
{ $push: { 'cards.$.categories.$.tags': { name: 'tag02', id: uuidv4(), is_selected: true } } }
);

Answer 1

You can not use multiple $ positional, for your case you can use single positional and arrayFilters,
The filtered positional operator $[<identifier>] identifies the array elements that match the arrayFilters conditions for an update operation,
db.collection(TABLE).updateOne({
list_id: 23,
"cards.categories.category": "section01"
},
{
$push: {
"cards.$.categories.$[elem].tags": {
name: "tag02",
id: uuidv4(),
is_selected: true
}
}
},
{
arrayFilters: [
{ "elem.category": "section01" }
]
})
Playground

Answer 2

In short, it is not possible.
Nested Arrays
The positional $ operator cannot be used for queries which traverse
more than one array, such as queries that traverse arrays nested
within other arrays, because the replacement for the $ placeholder is
a single value
https://docs.mongodb.com/manual/reference/operator/update/positional/
However, you may want to try $[]
Nested Arrays The filtered positional operator $[] can be
used for queries which traverse more than one array and nested arrays.
For an example, see Update Nested Arrays in Conjunction with $[].
https://docs.mongodb.com/manual/reference/operator/update/positional-filtered/#position-nested-arrays-filtered

Answer 3

You can use $[identifier]
db.collection.update({
"list_id": 23,
"cards.categories.category": "section01"
},
{
$push: {
"cards.$.categories.$[elem].tags": {
name: "tag02",
id: uuidv4(),
is_selected: true
}
}
},
{
arrayFilters: [
{
"elem.category": "section01"
}
],
multi: true
})
try it here