Exam AZ-220 All Questions

View all questions & answers for the AZ-220 exam

Exam AZ-220 topic 5 question 6 discussion

Actual exam question from Microsoft's AZ-220

Question #: 6
Topic #: 5

You have 1,000 devices that connect to an Azure IoT hub.
You are performing a scheduled check of deployed IoT devices.
You plan to run the following command from the Azure CLI prompt. az iot hub query --hub-name hub1 --query-command "SELECT * FROM devices WHERE connectionState = 'Disconnected'"
What does the command return?

A. the Device Disconnected events
B. the device twins
C. the Connections logs
D. the device credentials

Show Suggested Answer

Suggested Answer: B 🗳️
Device twin queries: IoT Hub exposes the device twins as a document collection called devices. For example, the following query retrieves the whole set of device twins:

SELECT * FROM devices -
Reference:
https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-devguide-query-language#device-and-module-twin-queries

by blackdog at June 4, 2020, 10:47 p.m.

Comments

Submit Cancel

blackdog

Highly Voted 4 years, 11 months ago

seems like it should return the device twins of the disconnected devices

upvoted 20 times

tita_tovenaar

3 years, 11 months ago

correct, confirmed here (see connectionState)> https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-devguide-identity-registry#device-heartbeat

upvoted 1 times

...

Yong2020

Highly Voted 4 years, 11 months ago

should be device twins.

upvoted 14 times

...

SanjuB

Most Recent 4 years, 3 months ago

the Device Disconnected events

upvoted 3 times

...

Bob

4 years, 3 months ago

Question says what does command return ? device twin is not something (telemetry or event or signal) which device return to hub. In my opinion A is correct.

upvoted 2 times

...

cup

4 years, 6 months ago

Indeed B...Tested with production data

upvoted 4 times

...

getazusername

4 years, 6 months ago

Device twin IoT Hub exposes the device twins as a document collection called devices. For example, the following query retrieves the whole set of device twins: SQL SELECT * FROM devices Source: https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-devguide-query-language

upvoted 1 times

...

Sudipta3009

4 years, 8 months ago

It will be Device Twin only for the disconnected Device

upvoted 3 times

...

ripin_aggarwal

4 years, 9 months ago

Correct option is B. The command returns the Device twin of the disconnected devices.

upvoted 5 times

...

not_a_robot

4 years, 10 months ago

Device twins

upvoted 5 times

...

not_a_robot

4 years, 10 months ago

Tried, returns data tiwns.

upvoted 4 times

...

meriadoc71

4 years, 11 months ago

Not disconnected devices The IoT Hub identity registry contains a field called connectionState. Only use the connectionState field during development and debugging. IoT solutions should not query the field at run time. For example, do not query the connectionState field to check if a device is connected before you send a cloud-to-device message or an SMS.

upvoted 1 times

...

theiotguy

4 years, 11 months ago

Yes. It should be Device twins. https://docs.microsoft.com/en-us/cli/azure/ext/azure-cli-iot-ext/iot/hub?view=azure-cli-latest#ext-azure-cli-iot-ext-az-iot-hub-query-examples

upvoted 5 times

valkyrieShadow

4 years, 7 months ago

Review the section labeled Device and module twin queries, displaying arbitrary JSON objects, which IoT Hub enables you to query device twins and module twins. Such as; "connectionState" here is the article: https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-devguide-query-language#device-and-module-twin-queries

upvoted 1 times

...