Error - The positional operator did not find, Mongo db update command not working in Meteor

help MongoDB
1

My stored doc in mongo is :

[{
  _id: 'Bd5r6vmb6bu5R2chQ',
  run_status: true,
  start_time: 2024-06-23T20:19:12.000Z,
  stop_time: 2024-06-23T20:19:12.000Z,
  strategies: [],
  summary: '{"pnl_per":0,"pnl":0,"profit":0,"loss":0,"win":0,"lose":0,"win_per":0,"ppt":0}',
  result: {}
}]

I am using meteor to develop the application with the built in mongo libs.

Now when I am trying to update the existing doc with some new attribute - “flag”: true. But ending up getting error :

(node:81184) UnhandledPromiseRejectionWarning: MongoServerError: The positional operator did not find the match needed from the query.

Here is my code to update the doc :

        let doc = LiveStrategies.find({}, {sort: {start_time: -1, limit: 1}}).fetch()[0];
        LiveStrategies.update( { _id: doc._id }, { $set: { flag: true } },
            (updateErr) => {
               if (updateErr) {
                  console.error('Error updating document:', updateErr);
                  return;
               }
                  console.log('Document updated successfully.');
               }
            }
        );

When i test with find query, its working perfectly fine and getting the doc correctly.

Appreciate your help on resolving this.

2

Although this seems not related to the error but first

Use findOne() instead of find().fetch()[0]

1 Like
3

My schema is :

StrategySchema = new SimpleSchema({
    name: {
        type: String,
        label: 'Algo Name'
    },
    instrument: {
        type: String,
        label: 'Instrument'
    }
});
LiveStrategySchema = new SimpleSchema({
    start_time: {
        type: Date,
        label: 'Start Time'
    },
    stop_time: {
        type: Date,
        label: 'Stop Time'
    },
    strategies: {
        type: Array,
        label: 'Strategies',
        optional: true
    },
    "strategies.$": StrategySchema
}

When I am setting the strategies attribute to Object type, not getting any error and update is working fine. But the strategies value is setting to empty.

4

Is the following correct way to define array of object :

strategies: {
        type: Array,
        label: 'Strategies',
        optional: true
    },
    "strategies.$": {
        type : StrategySchema,
        optional : true
    }
5

Finally i got the root cause : My StrategySchema schema is in diff file and not imported correctly due to which ending up with error while updating/inserting doc in to mongo db.