I need to update the dateP in the following structure with "2022-01-02", but it seems not an easy task:

{
  "_id": ObjectId("5c05984246a0201286d4b57a"),
  "_a": [
    {
      "_p": {
        "s": {
          "a": {}
        }
      }
    },
    {
      "_onlineStore": {}
    },
    {
      "_p": {
        "s": {
          "a": {
            "t": [
              {
                c: 4
              },
              {
                "dateP": "20200-09-20",
                "l": "English",
                "size": "XXL"
              },
              {
                c: 1
              }
            ]
          },
          c: {
            t: 2
          }
        }
      }
    }
  ]
}

playground

I attempted with arrayFilters, but without success as not all elements exist in all documents and some documents are pretty empty. Please advice.

MongoDB 4.2 community

CodePudding user response：

Believe that you need the filtered positional operator for _a array to check whether the document has the _p field or not.

db.collection.update({},
{
  $set: {
    "_a.$[a]._p.s.a.t.$[x].dateP": "2022-01-02"
  }
},
{
  arrayFilters: [
    {
      "a._p": {
        $exists: true
      }
    },
    {
      "x.dateP": "20200-09-20"
    }
  ]
})

Demo @ Mongo Playground