c - 亚马逊 dynamoDb ValidationException

Question

我正在使用 C 中的 aws-dynamo 库执行以下 dynamoDB 查询参数。

{ "TableName": "table4", "KeyConditionExpression": "#yr = :yyyy and ts between :letter1 and :letter2", "ExpressionAttributeNames": { "#yr": "userid" }, "ExpressionAttributeValues": { ":yyyy": "abc", ":letter1": 1, ":letter2": 2 } }

但是我得到了错误

"__type":"com.amazon.coral.validate#ValidationException","message":"1 validation error detected: Value null at 'hashKeyValue' failed to satisfy constraint: Member must not be null"

这是我的表结构

 table4
{
    "Table": {
        "TableSizeBytes": 66,
        "KeySchema": [
            {
                "AttributeName": "userid",
                "KeyType": "HASH"
            },
            {
                "AttributeName": "ts",
                "KeyType": "RANGE"
            }
        ],
        "CreationDateTime": 1464617195.039,
        "ItemCount": 3,
        "AttributeDefinitions": [
            {
                "AttributeName": "ts",
                "AttributeType": "N"
            },
            {
                "AttributeName": "userid",
                "AttributeType": "S"
            }
        ],
        "ProvisionedThroughput": {
            "ReadCapacityUnits": 1,
            "WriteCapacityUnits": 1,
            "LastDecreaseDateTime": 1464683346.007,
            "NumberOfDecreasesToday": 1
        },
        "TableStatus": "ACTIVE",
        "TableName": "table4",
        "TableArn": "arn:aws:dynamodb:us-east-1:456456456:table/table4"
    }
}

Answer 1

分区键必须在 keyconditionexpression 中。请包含分区键并尝试。查询dynamodb时，partition key是必须的。扫描 dynamodb 时，分区键是可选的。这是 dynamodb 中查询与扫描之间的主要区别。