$push is not supported in mongoose bulk operation-CodePudding

I am using the bulk operation in mongoose to update multiple documents in a concurrent manner.

The update data looks as below:

let docUpdates = [
    {
        id : docId1,
        status : "created",
        $push : {
            updates : {
                status: "created",
                referenceId : referenceId,
                createdTimestamp : "2022-06-14T00:00:00.000Z"
            }
        }
    },
    {
        id : docId2,
        status : "completed",
        $push : {
            updates : {
                status: "compelted",
                referenceId : referenceId,
                createdTimestamp : "2022-06-14T00:00:00.000Z"
            }
        }
    },
];

// Update documents using bulk operation
let bulkUpdate = Model.collection.initializeOrderedBulkOp();

for (let i = 0; i < docUpdates.length; i  ) {
    bulkUpdate.find({_id : docUpdates[i].docId}).updateOne({ $set : docUpdates[i]})
}

When I execute the above snippet, I get the below error.

(node:468) UnhandledPromiseRejectionWarning: MongoBulkWriteError: The dollar ($) prefixed field '$push' in '$push' is not allowed in the context of an update's replacement document. Consider using an aggregation pipeline with $replaceWith.
    at OrderedBulkOperation.handleWriteError (/usr/src/app/node_modules/mongoose/node_modules/mongodb/lib/bulk/common.js:884:22)

Could you please help in finding a work around for this error.

Thank you,
KK

CodePudding user response：

The problem isn't that $push isn't supported, it's that the way you pass the arguments in the update document, it's interpreted as a top-level field. See the documentation about field name considerations, specifically the section on document modifying updates.

This section of your code updateOne({ $set : docUpdates[i]}) is equivalent to the following:

updateOne({
  $set: {
    id: docId1,
    status: "created",
    $push: {
      updates: {
        status: "created",
        referenceId: referenceId,
        createdTimestamp: "2022-06-14T00:00:00.000Z"
      }
    }
  }
})

Because the $push is contained in the $set, you're telling MongoDB to set the value of a field named $push to a document with a field called updates, which has status, referenceId, and createdTimestamp fields.

What you want to do instead, is specify an update document with two different update operators. In other words, $push needs to be on the same level as the $set.

Something like:

updateOne({
  $set: {
    id: docId1,
    status: "created"
  },
  $push: {
    updates: {
      status: "created",
      referenceId: referenceId,
      createdTimestamp: "2022-06-14T00:00:00.000Z"
    }
  }
})

How you represent that in the docUpdates array is up to you. Maybe you can do something like:

let docUpdates = [
    {
        id : docId1,
        update : {
            $set : {
               status : "created"
            },
            $push : {
                updates : {
                    status: "created",
                    referenceId : referenceId,
                    createdTimestamp : "2022-06-14T00:00:00.000Z"
                }
            }
        }
    }
    // ... Other updates
]

And use it in the loop like:

bulkUpdate.find({_id : docUpdates[i].docId}).updateOne(docUpdates[i].update)