I try to set an attribute of an document inside an array to uppercase.
Here is the link to the mongodb playground <https://mongoplayground.net/p/BTP_h3kqK_S>

this is a document example

```
  {
    "_id": ObjectId("5e786a078bc3b3333627341e"),
    "value": {
      "items": [
        {
          "itemName": "alpha305102992",
          "itemNumber": ""
        },
        {
          "itemName": "beta305102630",
          "itemNumber": "P5000"
        },
        {
          "itemName": "gamma305102633 ",
          "itemNumber": ""
        }
      ]
    }
  }

```

I try to set the "itemName" to upper case.

My desired result would be:

```
  {
    "_id": ObjectId("5e786a078bc3b3333627341e"),
    "value": {
      "items": [
        {
          "itemName": "ALPHA305102992",
          "itemNumber": ""
        },
        {
          "itemName": "BETA305102630",
          "itemNumber": "P5000"
        },
        {
          "itemName": "GAMMA305102633 ",
          "itemNumber": ""
        }
      ]
    }
  }

```