mongo operator to update all matching items in an array

Question

messages: [
    {
        user: "5c57c85a9354fa24ad749137",
        text: "hello",
        unread: true
    },
    {
        user: "5c57c85a9354fa24ad749137",
        text: "world",
        unread: true
    }
]

I am trying to update all array elements where id does not match given id with the $[] but nothing happens

ChatSchema.update(
        {_id: mongoose.Types.ObjectId(req.body.conversationId), "messages": {$elemMatch: {"user": {$ne: mongoose.Types.ObjectId(req.body.userId)}}}},
        {$set: {"messages.$[].unread": false}},
        {multi: true}
        ).exec()

And when I use the single $ operator it only updates the first element found.

I am using mongo version 4.0.6 with mongoose version 6.7.0

Ashh · Answer 1 · 2019-05-12T17:23:05.147

1

Matching criteria should be the $[identifier]

ChatSchema.update(
  { "_id": mongoose.Types.ObjectId(req.body.conversationId) }},
  { "$set": { "messages.$[msg].unread": false }},
  { "arrayFilters":[{ "msg.user": { "$ne": mongoose.Types.ObjectId(req.body.userId) }}] }
)

edited May 12 '19 at 17:23

answered May 12 '19 at 17:07

Ashh

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I tryed it out and same result, nothing happens – I'm not human May 12 '19 at 17:23
Remove `$ne` operator and check whether it works or not and then add `$ne` – Ashh May 12 '19 at 17:29
No, it does not update with or without the $ne operator, but it does update when I use a single $ instead of $[msg], the problem is that it only updates the first match – I'm not human May 12 '19 at 17:36
@I'mnothuman Run this command `db.adminCommand( { setFeatureCompatibilityVersion: "3.4" })` – Ashh May 12 '19 at 17:51
Pls have a look https://stackoverflow.com/questions/51777183/cannot-use-the-part-to-traverse-the-element/51807509#51807509 – Ashh May 12 '19 at 18:06
Still you cannot able to explain what is not working – Ashh May 13 '19 at 16:34
Ok got it. Run this `db.adminCommand( { setFeatureCompatibilityVersion: "4.0.6" })` – Ashh May 13 '19 at 17:01
I also ran that and got no results – I'm not human May 13 '19 at 17:03
It does not give any result it just sets the `setFeatureCompatibilityVersion` of your database. Have look at the answer mentioned in the above comments – Ashh May 13 '19 at 17:04
No, I mean that I set it to that version and ran the query and nothing happened – I'm not human May 13 '19 at 17:06

mongo operator to update all matching items in an array

1 Answers1