物联网中心自定义规则

问题描述

目前正在寻求有关此网站 https://docs.microsoft.com/en-us/azure/iot-central/core/howto-create-custom-rules 代码的帮助。在使用使用查询来检测断开连接的 deviceid 的流分析作业时，它返回 null。请参阅如下：[断开连接的设备的所有 deviceid 返回空值，但时间戳在那里。][1]

这是我使用的查询。

with
LeftSide as
(
    SELECT
    -- Get the device ID from the message Metadata and create a column
    GetMetadataPropertyValue([centraltelemetry],'[EventHub].[IoTConnectiondeviceid]') as deviceid1,EventEnqueuedUtcTime AS time1
    FROM
    -- Use the event enqueued time for time-based operations
    [centraltelemetry] TIMESTAMP BY EventEnqueuedUtcTime
),RightSide as
(
    SELECT
    -- Get the device ID from the message Metadata and create a column
    GetMetadataPropertyValue([centraltelemetry],'[EventHub].[IoTConnectiondeviceid]') as deviceid2,EventEnqueuedUtcTime AS time2
    FROM
    -- Use the event enqueued time for time-based operations
    [centraltelemetry] TIMESTAMP BY EventEnqueuedUtcTime
)

SELECT
    LeftSide.deviceid1 as deviceid,LeftSide.time1 as time
INTO
    [emailnotification]
FROM
    LeftSide
    LEFT OUTER JOIN
    RightSide 
    ON
    LeftSide.deviceid1=RightSide.deviceid2 AND DATEDIFF(second,LeftSide,RightSide) BETWEEN 1 AND 120
    where
    -- Find records where a device didn't send a message 120 seconds
    RightSide.deviceid2 is NULL
```[enter image description here][2]


  [1]: https://i.stack.imgur.com/CLOQv.png
  [2]: https://i.stack.imgur.com/IU3SX.png

解决方法

由于流分析查询使用来自事件中心的遥测作为其输入，如果您遵循了完整的设置教程，请告诉我吗？如果是，您是否看到带有设备 ID 的功能日志消息？

另外，您是否收到 SendGrid 发送的带有设备 ID 的电子邮件？为了进一步分析，您能否还确认您的流分析作业正在接收来自事件中心的输入？