How can i update an object

Question

Hello, i got a problem  
  
I use DynamoDB with Serverless.   
I have a request that allows me to update an item from my table. But one of the objects of this item is like this :  
  
"example1":{  
       "example2":{  
              "name1" : "blabla"  
       }  
}  
I want to add values in example2, like "name2", "name3" ...  
My request with UpdateExpression and ExpressionAttributeValues looks like this :  
  
let params = {  
                ...  
                UpdateExpression: "SET example1.example2.name2 = :name2, example1.example2.name3 = :name3",  
                ExpressionAttributeValues: {   
                    ":name2": name2,  
                    ":name3" : name3  
                },  
                ...  
                ReturnValues: 'UPDATED_NEW'  
            }  
And when i run my request i got an answer like this "message":"The document path provided in the update expression is invalid for update"  
  
Can you help me if you already have something like this ?  
  
Thanks  
  
Best regards

Answer

Yes, that's work  
  
My mistake was that one of my values ​​had to be created in a new object, but since the object did not exist, it did not understand the path.  
  
Thanks for your help

Answer

I tried the following:  
  
#Existing item json:

```
c:\PADMA\UTILS\SCRIPTS>aws dynamodb scan --table-name example
{
    "Items": [
        {
            "pk": {
                "N": "1"
            },
            "example1": {
                "M": {
                    "example2": {
                        "M": {
                            "name2": {
                                "S": "a"
                            },
                            "name1": {
                                "S": "blabla"
                            }
                        }
                    }
                }
            },
            "sk": {
                "S": "key"
            }
        }
    ],
    "Count": 1,
    "ScannedCount": 1,
    "ConsumedCapacity": null
}
```

#Update command:

```
table.update_item(
    Key={
        'pk': pk,
        'sk': sk
    },
    UpdateExpression="set example1.example2.name3=:x",
    ExpressionAttributeValues={
        ':x': "new value"
    },
    ReturnValues="UPDATED_NEW"
)
```

#Updated item json:

```
c:\PADMA\UTILS\SCRIPTS>aws dynamodb scan --table-name example
{
    "Items": [
        {
            "pk": {
                "N": "1"
            },
            "example1": {
                "M": {
                    "example2": {
                        "M": {
                            "name1": {
                                "S": "blabla"
                            },
                            "name2": {
                                "S": "a"
                            },
                            "name3": {
                                "S": "new value"
                            }
                        }
                    }
                }
            },
            "sk": {
                "S": "key"
            }
        }
    ],
    "Count": 1,
    "ScannedCount": 1,
    "ConsumedCapacity": null
}
```

Is this what you are trying to do? I am getting the expected results. I followed this tutorial: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GettingStarted.Python.01.html  
Can you try this out. And let me know if you are still having trouble with this?

Answer

Hi, I am reviewing this now, and will send you an update once I have more information. Thank you.

How can i update an object

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