ArrayFilters for nested MongoDB schema

Question

I have the following MongoDB document and I'm trying to update the selected answer object in a nested array.

{
   "days":[
      {
         "data":{
            "average_score":{
               "$numberDecimal":"80"
            },
            "metabolic_score":{
               "$numberDecimal":"80"
            },
            "cardio_score":{
               "$numberDecimal":"80"
            },
            "glucose_levels":[
               {
                  "_id":{
                     "$oid":"5fdf461407a0a61cb7593bdb"
                  },
                  "start_date":"eee",
                  "end_date":"eee",
                  "value":{
                     "$numberDecimal":"80"
                  }
               }
            ],
            "heart_rates":[
               
            ],
            "summaries":[
               {
                  "actions":[
                     
                  ],
                  "_id":{
                     "$oid":"5fdf5a8182bb38276953c3dc"
                  },
                  "questions":[
                     
                  ]
               },
               {
                  "actions":[
                     
                  ],
                  "_id":{
                     "$oid":"5fdf5b71cac79b28cc840e2b"
                  },
                  "questions":[
                     {
                        "answers":[
                           "gugu",
                           "guru?"
                        ],
                        "_id":{
                           "$oid":"5fdf5b71cac79b28cc840e2d"
                        },
                        "text":"xxxx",
                        "selected_answer":"gugu!"
                     }
                  ]
               }
            ],
            "moods":[
               {
                  "_id":{
                     "$oid":"5fdf478ceec5901d4614188a"
                  },
                  "labels":[
                     
                  ]
               },
               {
                  "_id":{
                     "$oid":"5fdf4c3affa900202d89fa7a"
                  },
                  "labels":[
                     
                  ]
               }
            ]
         },
         "_id":{
            "$oid":"5fdf461407a0a61cb7593bdc"
         },
         "day":"18-12-2020"
      }
   ]
}

Currently, the code that I'm using is following:

User.findOneAndUpdate(
    {  _id: getUserId(req), "days.day": req.body.day},
    { $push: {"days.$.data.summaries.$[summ].questions.$[quest].selected_answer": req.body.selected_answer}},
    { arrayFilters: [{"summ._id": ObjectID("5fdf5b71cac79b28cc840e2d")}, {"quest._id": ObjectID("5fdf5b71cac79b28cc840e2d")}]},
    (err, user) => {
          if (err) {
            res.status(500).send({data: { message: err }});
            return;
          }
          else if (user) {
            res.status(200).send({data: { message: "updated!"}})
          }  
        }
    )

After the request gets executed it says "updated!" but the selected_answer entry is not actually updated. What am I missing? Somehow, it doesn't find the proper path.

Answer 1

The correct way of updating an existing entry is:

User.findOneAndUpdate(
    {  _id: getUserId(req), "days.day": req.body.day},
    { $set: {"days.$.data.summaries.$[summ].questions.$[quest].selected_answer": req.body.selected_answer}},
    { arrayFilters: [{"summ._id": ObjectID("5fdf5b71cac79b28cc840e2d")}, {"quest._id": ObjectID("5fdf5b71cac79b28cc840e2d")}]},
    (err, user) => {
          if (err) {
            res.status(500).send({data: { message: err }});
            return;
          }
          else if (user) {
            res.status(200).send({data: { message: "updated!"}})
          }  
        }
    )