IOT Central Custom Rules

Question

Currently seeking assistance with the code on this site https://learn.microsoft.com/en-us/azure/iot-central/core/howto-create-custom-rules. Upon using the stream analytics job that uses a query to detect a disconnected deviceId, it returns null. Please see as follows:[all deviceId's for the disconnected device return a null, but timestamp is there.][1]

This is the query I used.

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

Answer 1

Since the Stream Analytics query uses the telemetry from the event hub as its input, can you please let me know if you followed the complete tutorial for the setup? In case yes, do you see the function log messages with the device id?

Also, do you receive the email from SendGrid with the deviceid? In order to analyze further, can you please also confirm that your stream analytics job is receiving inputs from the event hub?