How to access an existing record when using ReturnValuesOnConditionCheckFailure: 'ALL_OLD'?

[mahdi]

Hi,

I'm trying to use put() with ReturnValuesOnConditionCheckFailure: 'ALL_OLD' to return the existing record if it already exists; while debugging I can see that error.Item is available and contains the existing record but for some reason I can't access that at runtime:

try {
      const { data: response } = await this.Entity
        .put({
          id: 'id',
        })
        .where(({ id }, { notExists }) => notExists(id))
        .go({
          params: { ReturnValuesOnConditionCheckFailure: 'ALL_OLD' },
          originalErr: true,
        });

      return response.id;
      );
    } catch (error: unknown) {
      if (
        error instanceof ElectroError &&
        error.cause instanceof DynamoDBServiceException &&
        error.cause.name === 'ConditionalCheckFailedException'
      ) {
          const existingItem = error.Item;
          return existingItem.id;
        }
        throw error;
      }
    }

What's the proper way of accessing an existing item when catching the ConditionalCheckFailedException exception?

[tom-g-dane]

I'm interested in this too, I haven't actually tested this out though. I found this thread on the AWS SDK, looks like you need SDK version 3.363.0. Which version are you running?

[anatolzak]

@mahdi @tom-g-dane The following PR #552 adds first-class support for this use case. The PR should hopefully get merged within the next couple of days