Question

我正在尝试通过Stream Analytics将我的IoT Hub数据发送到Power BI。只要IoT设备的json数据中不包含任何数组，这种方法就可以正常工作。

我的问题是：如何修改我的Stream Analytics查询，以便PowerBI能够将数据解释为数组/表格？我如何TIMESTAMP BY每个数组元素（使用“timecreated”）？

我发送给IoT Hub的json字符串如下所示：

{"sensordata":[{"name":"Temp_0","value":3,"timecreated":"2016-11-09T11:08:00Z"},
{"name":"Temp_0","value":7,"timecreated":"2016-11-09T11:08:02Z"},
{"name":"Temp_1","value":2,"timecreated":"2016-11-09T11:08:04Z"}]}

Stream Analytics从物联网中心收到的内容：

[{"sensordata":[{"name":"Temp_0","value":3,"timecreated":"2016-11-09T11:08:00.0000000Z"},
{"name":"Temp_0","value":7,"timecreated":"2016-11-09T11:08:02.0000000Z"},
{"name":"Temp_1","value":2,"timecreated":"2016-11-09T11:08:04.0000000Z"}],    
"EventProcessedUtcTime":"2016-11-09T10:08:57.9325156Z","PartitionId":0,
 "EventEnqueuedUtcTime":"2016-11-09T10:08:47.8050000Z","IoTHub":
{"MessageId":null,"CorrelationId":null,"ConnectionDeviceId":"toCloudDevice",
"ConnectionDeviceGenerationId":"607350268321425367",
"EnqueuedTime":"0001-01-01T00:00:00.0000000","StreamId":null}}]

我的Stream Analytics查询如下所示：

SELECT sensordata.ArrayValue AS data,
  COUNT(*)
INTO
  [transmit-data]
FROM
  [receive-data] AS e
CROSS APPLY GetArrayElements(e.sensordata) AS sensordata
GROUP BY
  sensordata,
  tumblingWindow(Second, 10)

IoT Hub向Power BI发送的内容：

[{"data":{"name":"Temp_1","value":2,"timecreated":"2016-11-09T11:08:04.0000000Z"},
"count":1},{"data":{"name":"Temp_0","value":7,"timecreated":"2016-11-09T11:08:02.0000000Z"},
"count":1},{"data":{"name":"Temp_0","value":3,"timecreated":"2016-11-09T11:08:00.0000000Z"},
"count":1}]

PowerBI无法以合理的方式解释这些数据。

我希望能够生成图形，例如在x轴上有时间并且在y轴上具有Temp_0的值。

关于这个问题的任何想法？非常感谢您的帮助。

（顺便说一句：来自IoT设备的json字符串有不同数量的数组元素！）

Answer 1

Power BI不允许复杂的对象，如数组或记录。您的案例中的问题是“数据”字段是记录。

请尝试以下查询：

SELECT 
    sensordata.ArrayValue.data.Name,
    sensordata.ArrayValue.data.Value,
    sensordata.ArrayValue.data.Timecreated,
    COUNT(*)
INTO
  [transmit-data]
FROM
  [receive-data] AS e
CROSS APPLY GetArrayElements(e.sensordata) AS sensordata
GROUP BY
  sensordata,
  tumblingWindow(Second, 10)

不幸的是，您今天无法在各个数组元素上应用TIMESTAMP BY。单个事件只能有一个时间戳有一个限制。但是，您可以将作业拆分为两个，其中第一个作业执行CROSS APPLY并将事件插入到中间事件中心，第二个作业执行TIMESTAMP BY和聚合

Azure流分析查询：将json数组数据发送到PowerBI

1 个答案: