List resources by from Azure by tag

I have the following simple piece of code for listing resources by tag from Azure, but I cannot get filter working. What am I doing wrong?

using Azure.Core;
using Azure.Identity;
using Azure.ResourceManager;
using Veeam.Core.Extensions;

string clientId = "...";
string tenantId = "...";
var clientSecret = "...";
string subscriptionId = "...";

// the code works with and operator but not works with or operator var filterTags = "tagName eq 'asdf' or tagValue eq '1234'";

var e = ArmEnvironment.AzurePublicCloud;
var credential = new ClientSecretCredential(tenantId, clientId, clientSecret);
var armClient = new ArmClient(credential);
var subscription = armClient.GetSubscriptionResource(new ResourceIdentifier("/subscriptions/" + subscriptionId));
var resourcesPageable= subscription.GetGenericResourcesAsync(filter: filterTags);
var tempResources = await resourcesPageable.ToListAsync();
Console.WriteLine(tempResources.Count);

The response from server is:

Status: 400 (Bad Request)
ErrorCode: InvalidFilterInQueryString

Content:                                                                                                                                          
{"error":{"code":"InvalidFilterInQueryString","message":"Invalid $filter 'tagName eq 'asdf' and tagValue '1234'' specified in the query string."}}

IntelliSense documentation says:

//For example, to filter for a tag name and value, use $filter=tagName eq 'tag1' and tagValue eq 'Value1'. When you filter by a tag name and value, the tags for each resource are not returned in the results.

Is it really the or operator not supported?

Is it really the or operator not supported?

Yes, only and operations are allowed in $filter tag to list the resources but not or operation. Refer MSDOC.

Try below operations to list the resources with tagname/tagvalue:

$filter=tagname eq '{tagname}'
$filter=tagname eq '{tagname}' and tagvalue eq '{tagvalue}'
$filter=startswith(tagname, '{tagname prefix}')

I have implemented the same with the below code:

using System;
using System.Threading.Tasks;
using Azure.Core;
using Azure.Identity;
using Azure.ResourceManager;
using Azure.ResourceManager.Resources;
using Azure.ResourceManager.Resources.Models;
using System.Data.Entity.Repository;

class Program
{
    static async Task Main(string[] args)
    {
        string clientId = "<Client_ID>";
        string tenantId = "<Tenant_ID>";
        var clientSecret = "<Client_secret>";
        string subscriptionId = "<Subscription_ID>";
        string filterTags = "tagname eq 'abc' and tagvalue eq '123'"; 

        var e = ArmEnvironment.AzurePublicCloud;
        var credential = new ClientSecretCredential(tenantId, clientId, clientSecret);
        var armClient = new ArmClient(credential);
        var subscription = armClient.GetSubscriptionResource(new ResourceIdentifier("/subscriptions/" + subscriptionId));
        var resourcesPageable = subscription.GetGenericResourcesAsync(filter: filterTags);
        var tempResources = new List<GenericResource>();

        await foreach (var resource in resourcesPageable)
        {
            tempResources.Add(resource);
        }

        Console.WriteLine($"Number of resources: {tempResources.Count}");

        foreach (var resource in tempResources)
        {
            Console.WriteLine($"Resource ID: {resource.Id}, Resource Name: {resource.Data.Name}, Resource Type: {resource.Data.ResourceType}");
        }

    }
}

Console Output: