Exception in reading list of Azure IoT devices in C# azure function

Question

I'm fetching list of Azure IoT devices using IoT hub sql query in C# function.

 var query = _registry.CreateQuery("SELECT deviceId,tags.SiteId FROM devices", 100);

I'm getting below error in function while debugging

System.Private.CoreLib: Exception while executing function: shared_iot_eventhub_reader_function. Microsoft.Azure.Devices: result type is Raw.

Same query works in Azure portal. What changes do I need to make in query to give me list of Azure IoT devices

I want to fetch a List of Azure IoT devices in my Azure IoT Hub

Answer 1

using Azure Function I was able to get the reading list of Azure IoT devices with Twin objects.

I have referred this MSDOC for IoT Hub query ,Function and for your comments @Dai

  
            var connectionString = "your connection string";
            var registryManager = RegistryManager.CreateFromConnectionString(connectionString);

            var query = registryManager.CreateQuery("SELECT * FROM devices", 100);
            while (query.HasMoreResults)
            {
                var page = await query.GetNextAsTwinAsync();
                foreach (var twin in page)
                {
              
                    log.LogInformation($"Device Id: {twin.DeviceId}");
                    log.LogInformation($"ModuleId :{twin.ModuleId}");
                    log.LogInformation($"Tags:{twin.Tags}");
                    log.LogInformation($"CloudToDeviceMessageCount :{twin.CloudToDeviceMessageCount}");
                    log.LogInformation($"StatusUpdatedTime :{twin.StatusUpdatedTime.ToString()}");
                    log.LogInformation($"twin.Properties:{twin.Properties.ToString()}");
                    log.LogInformation($"LastActivity :{ twin.LastActivityTime.ToString()}");
                    log.LogInformation($"Version: {twin.Version.ToString()}");
                }
            }

            await registryManager.CloseAsync();

            return new OkResult();
        

Output :