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 } }

但我收到了错误

"__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，必须使用分区键。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。

Answer 2

这是工作查询和表格结构。

{ TableName: 'table4',
KeyConditionExpression: '#userid = :userid AND #ts between :ts1 AND :ts2',
ExpressionAttributeNames: { '#userid': 'userid', '#ts': 'ts' },
ExpressionAttributeValues: { ':userid': 'user1', ':ts1': 1, ':ts2': 2 } }

查询输出： -

{"userid":{"S":"user1"},"ts":{"N":"1"}}

表格结构： -

    {"Table":{"AttributeDefinitions":  
      [{"AttributeName":"userid","AttributeType":"S"},
     {"AttributeName":"ts","AttributeType":"N"}],
"TableName":"table4","KeySchema":
[{"AttributeName":"userid","KeyType":"HASH"},{"AttributeName":"ts","KeyType":"RANGE"}],
"TableStatus":"ACTIVE",
"CreationDateTime":"2016-05-31T12:46:08.351Z",
"ProvisionedThroughput":{"LastIncreaseDateTime":"1970-01-01T00:00:00.000Z","LastDecreaseDateTime":"1970-01-01T00:00:00.000Z","NumberOfDecreasesToday":0,
"ReadCapacityUnits":10,"WriteCapacityUnits":10},
"TableSizeBytes":15,"ItemCount":1,"TableArn":
"arn:aws:dynamodb:ddblocal:000000000000:table/table4"}}

亚马逊dynamoDb ValidationException

2 个答案: