python - 如何扫描dynamodb中的所有项目？

Question

我有以下方法扫描 dynamo 数据库表中的所有项目

async def scan_all(self, parse_item: Callable[[dict], dict], **kwargs) -> List[dict]:
    response = await self._db.scan(**kwargs)
    response_items = response.get('Items', [])
    items = list(parse_item(item) for item in response_items)
    last_evaluated_key = response.get('LastEvaluatedKey', None)
    while last_evaluated_key is not None:
        response = await self._db.scan(ExclusiveStartKey=last_evaluated_key, **kwargs)
        response_items = response.get('Items', [])
        items.extend(parse_item(item) for item in response_items)
        last_evaluated_key = response.get('LastEvaluatedKey', None)
    return items

这是正确的方法还是我可以改进它？使用 LastEvaluatedKey 的最佳做法是什么？

Answer 1

嗯，我不确定这个更好，但这就是我的做法(阅读 dynamodb 文档):

Map<String, AttributeValue> lastKeyEvaluated = null;

    do {
        ScanRequest scanRequest = new ScanRequest().withTableName(TABLE_NAME)
                .withExclusiveStartKey(lastKeyEvaluated);
        ScanResult result = client.scan(scanRequest);
        for (Map<String, AttributeValue> item : result.getItems()) {

        }
    }while(lastKeyEvaluated != null);