CODEWITHSUNDEEP
pythonamazon-web-servicesamazon-dynamodbboto3
soBusted
soBusted

Reputation: 305

Can't seem to get Boto's dynamodb.update_item to work

I'm trying to use this Boto function, But can't seem to get it right.. Any idea? Doc Link

    tablename = 'name_table'
    response = dynamodb.update_item(
        TableName=tablename,
        Key={
            'name': 'Tony',
        },
        UpdateExpression="set name= :r",
        ExpressionAttributeValues={
            ':r': 'Ralph',
        },
        ReturnValues="UPDATED_NEW"
    )

This are the errors I get :

Invalid type for parameter Key.name, value: set(['Tony', 0]), type: <type 'set'>, valid types: <type 'dict'>

I've tried to change the name from str to dict, So now I'm with this error

ValueError: dictionary update sequence element #0 has length 1; 2 is required

Where to go from here ? Many thanks..

Upvotes: 0

Views: 121

Answers (2)

Jason Wadsworth
Jason Wadsworth

Reputation: 8885

The keys in the API you referenced expect the values to be DynamoDB attributes, so the Key should be like this:

{
    'name': {
        'S': 'Tony'
    }
}

The ExpressionAttributeValues should be like this:

{
    ':r': {
        'S': 'Ralph'
    }
}

So the whole thing looks like this:

    tablename = 'name_table'
    response = dynamodb.update_item(
        TableName=tablename,
        Key={
            'name': {
                'S': 'Tony'
             }
        },
        UpdateExpression="set name= :r",
        ExpressionAttributeValues={
            ':r': {
                'S': 'Ralph'
            }
        },
        ReturnValues="UPDATED_NEW"
    )

Upvotes: 1

Anirudh Panchangam
Anirudh Panchangam

Reputation: 498

The key cannot be a dictionary.

     tablename = 'name_table'
     response = dynamodb.update_item(
        TableName=tablename,
        Key="name = :name",
        UpdateExpression="set name= :r",
        ExpressionAttributeValues={
            ':r': 'Ralph',
            ':name': 'Tony'
        },
        ReturnValues="UPDATED_NEW"
    )

Upvotes: 0

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