使用 Java 查询 DynamoDB

Question

如何仅使用主键查询/扫描 DynamoDB 表？我能够从表中返回结果的唯一方法是下面的代码，我在其中设置了主键Id并Condition使用排序键添加了 a Date。有什么方法可以在不提供 的情况下查询表RangeKeyCondition？DynamoDataObject data = new DynamoDataObject();data.setId(userId);Condition rangeKeyCondition = new Condition()    .withComparisonOperator(ComparisonOperator.BEGINS_WITH)    .withAttributeValueList(new AttributeValue().withS("2018"));DynamoDBQueryExpression queryExpression = new DynamoDBQueryExpression()    .withHashKeyValues(data)    .withRangeKeyCondition("Date", rangeKeyCondition)    .withConsistentRead(false);PaginatedList<DynamoDataObject > result = AWSProvider.getInstance().getDynamoDBMapper().query(DynamoDataObject.class, queryExpression);Log.d(TAG, "PaginatedList length: " + result.size());

Answer 1

弄清楚了。您不必包括withRangeKeyCondition：

DynamoDataObject data = new DynamoDataObject();

data.setId(userId);

DynamoDBQueryExpression queryExpression = new DynamoDBQueryExpression()

    .withHashKeyValues(data)

    .withConsistentRead(false);

PaginatedList<DynamoDataObject > result = AWSProvider.getInstance().getDynamoDBMapper().query(DynamoDataObject.class, queryExpression);

Log.d(TAG, "PaginatedList length: " + result.size());