MongoDB update arrays entry-CodePudding

I have a document to Mongodb update array of objects like this:

``` code ```

{
"myArray": [
        {
          "Key1": "string",
          "key2": {
            "entry": "aaa"
          }
        },
        {
          "Key1": "string",
          "key2": {
            "entry": "bbb"
          }
        }
      ]
}

``` code ```

And I want to modify the key2 field in each object of myArray. The expected result should be :

``` code ```
{
"myArray": [
        {
          "Key1": "string",
          "key2Modified":"aaa"
        },
        {
          "Key1": "string",
          "key2Modified":"bbb"
        }
      ]
}
``` code ```

Any help please ?

CodePudding user response：

use $map in $set

db.collection.update({},
[
  {
    $set: {
      "myArray": {
        $map: {
          input: "$myArray",
          as: "a",
          in: {
            Key1: "$$a.Key1",
            key2Modified: "$$a.key2.entry"
          }
        }
      }
    }
  }
])

mongoplayground