Boto3 updating multiple values

Question

in the boto3 documentation updating an item is described by this example:

table.update_item(
    Key={
        'username': 'janedoe',
        'last_name': 'Doe'
    },
    UpdateExpression='SET age = :val1',
    ExpressionAttributeValues={
        ':val1': 26
    }
)

But what am i supposed to do, if i want to update several values of the item. I couldn't find any information on this. Can anybody help? Thank you!

EDIT:

Ok, it seems to work like this, can anybody confirm wether this is the right way. Just to be sure i'm not doing anything totally wrong here.

table.update_item(
                    Key={
                        'id': item['id']
                    },
                    UpdateExpression='SET value1 = :val1, value2 = :val2',
                    ExpressionAttributeValues={
                        ':val1': someValue1,
                        ':val2': someValue2
                    }
                )

Thanks!

Yes that is correct. It's documented clearly here: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.Modifying.html — Mark B, Jun 09 '16 at 16:39

score 25 · Accepted Answer · edited Jul 26 '16 at 05:56

25

Yes, that's the way to do. Even many actions can be done in single expression as shown here. For ex: multiple 'PUT' and 'DELETE' in single expression.

Snapshot showing the example from document

edited Jul 26 '16 at 05:56

J. Chomel

8,193
15
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answered Jul 25 '16 at 21:59

Venkatesh Wadawadagi

2,793
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1

Hey, that's very interesting. Thank you very much for your answer! – weka1 Jul 26 '16 at 08:43

score -1 · Answer 2 · answered Jan 31 '20 at 22:00

For others finding this, theres a library you can use to help with the weird boto3 stuff like ExpressionAttributeValues. This way you can make normal developer/human calls.

https://github.com/rayepps/dynamof

db(update(
  table_name='users',
  key={ 'id': item['id'] },
  attributes={
      'age': 26,
      'name': 'Carl'
  }))

disclaimer: I wrote it

Boto3 updating multiple values

2 Answers2