Mongodb update deeply nested subdocument

Question

I have a document structure that is deeply nested, like this:

{id: 1, 
 forecasts: [ { 
             forecast_id: 123, 
             name: "Forecast 1", 
             levels: [ 
                { level: "proven", 
                  configs: [
                            { 
                              config: "Custom 1",
                              variables: [{ x: 1, y:2, z:3}]
                            }, 
                            { 
                              config: "Custom 2",
                              variables: [{ x: 10, y:20, z:30}]
                            }, 
                    ]
                }, 
                { level: "likely", 
                  configs: [
                            { 
                              config: "Custom 1",
                              variables: [{ x: 1, y:2, z:3}]
                            }, 
                            { 
                              config: "Custom 2",
                              variables: [{ x: 10, y:20, z:30}]
                            }, 
                    ]
                }
            ]
        }, 
    ]

}

I'm trying to update the collection to insert a new config, that looks like this:

newdata =  {
  config: "Custom 1", 
  variables: [{ x: 111, y:2222, z:3333}]
}

I'm trying something like this in mongo (in Python):

db.myCollection.update({"id": 1, 
                        "forecasts.forecast-id": 123, 
                        "forecasts.levels.level": "proven", 
                        "forecasts.levels.configs.config": "Custom 1"
                         },
                         {"$set": {"forecasts.$.levels.$.configs.$": newData}}
                      )

I'm getting "Cannot apply the positional operator without a corresponding query field containing an array" error though. What is the proper way to do this in mongo? This is mongo v2.4.1.

Answer 1

EASY SOLUTION FOR Mongodb 3.2+ https://docs.mongodb.com/manual/reference/method/db.collection.replaceOne/

I had a similar situation and solved it like this. I was using mongoose, but it should still work in vanilla MongoDB. Hope it's useful to someone.

const MyModel = require('./model.js')
const query = {id: 1}

// First get the doc
MyModel.findOne(query, (error, doc) => {

    // Do some mutations
    doc.foo.bar.etc = 'some new value'

    // Pass in the mutated doc and replace
    MyModel.replaceOne(query, doc, (error, newDoc) => {
         console.log('It worked!')
    })
}

Depending on your use case, you might be able to skip the initial findOne()

Answer 2

Given how MongoDB doesn't appear to provide a good mechanism for this, I find it prudent to use mongoose to simply extract the element from the mongo collection using .findOne(...), run a for-loop search on its relevant subelements (seeking by say ObjectID), modify that JSON, then do Schema.markModified('your.subdocument'); Schema.save(); It's probably not efficient, but it is very simple and works fine.

Answer 3

Okkk.we can update our nested subdocument in mongodb.this is our schema.

var Post = new mongoose.Schema({
    name:String,
    post:[{
        like:String,
        comment:[{
            date:String,
            username:String,
            detail:{
                time:String,
                day:String
            }
        }]
    }]
})

solution for this schema

  Test.update({"post._id":"58206a6aa7b5b99e32b7eb58"},
    {$set:{"post.$.comment.0.detail.time":"aajtk"}},
          function(err,data){
//data is updated
})