MongoDB query to update array object in index N?

Use update() in MongoDB to update array object. The usage of dot notation is also required. Let us create a collection with documents −

> db.demo489.insertOne(
... {
...
...
...    details : [{
...       id : 101,
...       "Info1" : {
...          "StudentName" : "Chris"
...       },
...       "Info2" : {
...          "TeacherName" : "David"
...       }
...    },
...    {
...       id : 102,
...       "Info1" : {
...          "StudentName" : "Carol"
...       },
...       "Info2" : {
...          "TeacherName" : "Mike"
...       }
...    }
...  
... ]
... }
... );
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e8356e0b0f3fa88e22790ba")
}

Display all documents from a collection with the help of find() method −

> db.demo489.find();

This will produce the following output −

{ "_id" : ObjectId("5e8356e0b0f3fa88e22790ba"), "details" : [ { "id" : 101, "Info1" : {
"StudentName" : "Chris" }, "Info2" : { "TeacherName" : "David" } }, { "id" : 102, "Info1" : {
"StudentName" : "Carol" }, "Info2" : { "TeacherName" : "Mike" } } ] }

Following is the query to update array object −

> db.demo489.update({"details.id":102},
...    {$set: {"details.$.Info1.StudentName":"Robert",
...       "details.$.Info2.TeacherName":"John",
...       "details.$.CountryName" : "US"
...
...    }
... })
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

Display all documents from a collection with the help of find() method −

> db.demo489.find().pretty();

This will produce the following output −

{
   "_id" : ObjectId("5e8356e0b0f3fa88e22790ba"),
   "details" : [
      {
         "id" : 101,
         "Info1" : {
            "StudentName" : "Chris"
         },
         "Info2" : {
            "TeacherName" : "David"
         }
      },
      {
         "id" : 102,
         "Info1" : {
            "StudentName" : "Robert"
         },
         "Info2" : {
            "TeacherName" : "John"
         },
         "CountryName" : "US"
      }
   ]
}