How to toggle a boolean field in an array using $set and positional operator

[schach_schach]

I have documents in my collection in the format

  {
    "_id": "61a02dc3e044cc34ce8a3a2f",
    "name": "Product 1",
    "status": true,
    "items": [
      {
        "_id": "61a02dc3e044cc34ce8a3a30",
        "foodName": "Item 1",
        "price": 10,
        "status": true
      },
      {
        "_id": "61a02dc3e044cc34ce8a3a31",
        "foodName": "Item 2",
        "price": 20,
        "status": false
      }
    ]
  }

Now lets say I want to toggle the status of where items._id : 61a02dc3e044cc34ce8a3a31. I tried with the positional operator but it simply doesn’t give me the result

This is the query I tried

db.collection.update({
  _id: "61a02dc3e044cc34ce8a3a2f",
  "items._id": "61a02dc3e044cc34ce8a3a31"
},
{
  $set: {
    "items.$.status": {
      $not: [
        {
          $eq: [
            "$items.$.status",
            true
          ]
        }
      ]
    }
  }
})

I get back the below which is not what I want

  {
    "_id": "61a02dc3e044cc34ce8a3a2f",
    "items": [
      {
        "_id": "61a02dc3e044cc34ce8a3a30",
        "foodName": "Item 1",
        "price": 10,
        "status": true
      },
      {
        "_id": "61a02dc3e044cc34ce8a3a31",
        "foodName": "Item 2",
        "price": 20,
        "status": {
          "$not": [
            {
              "$eq": [
                "$items.$.status",
                true
              ]
            }
          ]
        }
      }
    ],
    "name": "Product 1",
    "status": true
  }

I mean it doesn’t read the conditions just assigns the condition object as the value. Here is the mongo playground link I tested with

Is this not possible. Any alternatives?

[steevej (Steeve Juneau)]

You need the following:

Updates with Aggregation Pipeline — MongoDB Manual

[Durrah_Khan]

db.demo.bulkWrite([
{
updateOne: {
filter: { items: { $elemMatch: { _id: “61a02dc3e044cc34ce8a3a31” } } },
update: { $set: { “items.$.status”: true } }
}
}
])

[steevej (Steeve Juneau)]

@Durrah_Khan

update: { $set: { “items.$.status”: true } }

Not quite a working solution as the problem is toggle a boolean field. What you share sets it to true even when it is already true. When true it has to be set to false.

[schach_schach]

hi thanks for the reply
but how do i access the positional operator in an aggregation pipeline. I’m not quite sure how to do it

[steevej (Steeve Juneau)]

Sorry for the delay. I don’t know.

I am pretty sure that you can achieve the toggle with $map along the lines:

{ $set : {
  "items" : { $map : {
    "input" : "$items" ,
    "as" : "item" ,
    "in" : { "$cond" : {
      "if" : { "$eq" : [ "$$item._id" , "61a02dc3e044cc34ce8a3a31" ] } ,
      "then" : {  "$mergeObjects : [
        "$$item" ,
        { "status" : { "$not" : [ "$$item.status" ] } }
      ] } ,
      "else" : "$$item"
    } }
  } }
} }