Query Devices on Azure IoT Hub STARTS_WITH MAC Address

I'm trying to filter the devices on my IoT Hub, I need to get only devices that starts with specific Mac Address.

This is the query I'm trying:

SELECT * FROM devices where starts_with(deviceId, 'D8B0')

But I'm getting

Internal Server Error

I also tried:

SELECT * FROM devices where index_of(deviceId, 'D8B0') = 0

With same results

I tried from the Query Explorer on the Azure Portal, Postman and .Net SDK

Solution

I'm afraid you cannot achieve what you're looking for using a query. As per the documentation, "when querying twins and jobs the only supported function is: IS_DEFINED(property)"

You can however use the starts_with() operator in your routing rule, so maybe that will do the trick for you. If not, you may want to add a specific tag to your device twins to indicate their 'type' as per your rule on MAC address prefix.