Using MongoDB $pull to delete documents within an Array - mongodb

Question

I have a collection in MongoDB, which is like following:
{
"_id" : "5327010328645530500",
"members" : [
{
"participationCoeff" : 1,
"tweetID" : "5327010328645530500"
},
{
"participationCoeff" : 1,
"tweetID" : "2820402625046999289"
},
{
"participationCoeff" : 0.6666666666666666,
"tweetID" : "6122060484520699114"
},
{
"participationCoeff" : 1,
"tweetID" : "4656669980325872747"
}
]
}
{
"_id" : "2646953848367646922",
"members" : [
{
"participationCoeff" : 1,
"tweetID" : "2646953848367646922"
},
{
"participationCoeff" : 0.75,
"tweetID" : "7750833069621794130"
},
{
"participationCoeff" : 0.5,
"tweetID" : "6271782334664128453"
}
]
}
Basically, collection have clusters, where a cluster has an _id field and a members field. Members field is an array of documents, having following format.
{
"participationCoeff" : 1,
"tweetID" : "5327010328645530500"
}
Now, from time to time, I have to delete these sub-documents in members attribute of cluster document, by matching tweetID.
However, I'm not able to find a query to achieve this effect. Basically, a tweetID will participate in many clusters, and hence will appear in multiple sub-documents of 'members' attribute of various clusters. I want to supply a bulk $pull operation, where I can remove all the sub-documents in all the clusters (i.e. their members attribute) which match on a particular tweetID.
Some help and intuition will be really helpful.

Answer 1

That's exactly what the $pull operator does, so in the shell you could use an update like:
db.clusters.update({},
{$pull: {members: {tweetID: '5327010328645530500'}}},
{multi: true})
Set the multi option so that every document is updated, not just the first one.

Answer 2

This will delete multiple tweets in a single query just pass an array to $in:-
db.clusters.update({},
{$pull: {members: {$in: [ {tweetID: '5327010328645530500'},{"tweetID" : "2820402625046999289"} ] } } },
{multi: true});
The above method doesnt work in mongoose
so for mongoose do:-
db.clusters.update({},
{$pull: {members:[ {tweetID: '5327010328645530500'},{"tweetID" : "2820402625046999289"} ] } });

Answer 3

In the meantime the update method is deprecated. Therefore one possible up-to-date solution to this would be using the updateMany method instead.
db.clusters.updateMany({},
{$pull: {members: {tweetID: '5327010328645530500'}}})

Answer 4

NOTE: Used in "mongoose": "^5.12.13".
As for today June 22nd, 2021, you can use $in and $pull mongodb operators to remove items from an array of documents :
Parent Document :
{
"name": "June Grocery",
"description": "Remember to pick Ephraim's favorit milk",
"createdDate": "2021-06-09T20:17:29.029Z",
"_id": "60c5f64f0041190ad312b419",
"items": [],
"budget": 1500,
"owner": "60a97ea7c4d629866c1d99d1",
}
Documents in Items array :
{
"category": "Fruits",
"bought": false,
"id": "60ada26be8bdbf195887acc1",
"name": "Kiwi",
"price": 0,
"quantity": 1
},
{
"category": "Toiletry",
"bought": false,
"id": "60b92dd67ae0934c8dfce126",
"name": "Toilet Paper",
"price": 0,
"quantity": 1
},
{
"category": "Toiletry",
"bought": false,
"id": "60b92fe97ae0934c8dfce127",
"name": "Toothpaste",
"price": 0,
"quantity": 1
},
{
"category": "Toiletry",
"bought": false,
"id": "60b92ffb7ae0934c8dfce128",
"name": "Mouthwash",
"price": 0,
"quantity": 1
},
{
"category": "Toiletry",
"bought": false,
"id": "60b931fa7ae0934c8dfce12d",
"name": "Body Soap",
"price": 0,
"quantity": 1
},
{
"category": "Fruit",
"bought": false,
"id": "60b9300c7ae0934c8dfce129",
"name": "Banana",
"price": 0,
"quantity": 1
},
{
"category": "Vegetable",
"bought": false,
"id": "60b930347ae0934c8dfce12a",
"name": "Sombe",
"price": 0,
"quantity": 1
},
Query :
MyModel.updateMany(
{ _id: yourDocumentId },
{ $pull: { items: { id: { $in: itemIds } } } },
{ multi: true }
);
Note: ItemIds is an array of ObjectId.
See below :
[
'60ada26be8bdbf195887acc1',
'60b930347ae0934c8dfce12a',
'60b9300c7ae0934c8dfce129'
]