how to conditionally add filter fields and value in Django

Consider the below sample model.

class Server(models.Model):
    os = models.CharField(max_length=30)
    server_owner = models.CharField(max_length=30)
    server_located = models.CharField(max_length=20)
    server_name = models.CharField(max_length=20)
    ...
    ...

In the future, this model will have more fields.

So from the request, I would get list of values that I need to filter. Consider the below sample data.

os_list = ["Windows", "Linux", "Mac"]
server_owner_list = ["John", "Will", "Jake", "Shyam"],
server_located = ["India", "USA"]
server_name = []
...
...
...

I want to exclude the lists which are empty. From the above example, server_name is an empty list. So while filtering from the Server model I want to add os_list, server_owner_list and server_located and exclude the server_name. In the future, more fields will be added to the DB model, and I might receive an extra list of values from the client request. which could have empty list of array. So I don't want to write a bunch of if-else conditions to check which lists are empty and not empty.

Can anyone please help me how can I write scalable ORM for this.

Edit:

so from a frontend react table, I will use column filtering. from the column dropdown, if the user selects the data from the column dropdown, selected data will be there in the array format. If the user resets the data which he had selected previously will be an empty array. so when the user presses the filter the data will be passed to the backend.

So in the backend, I would receive the empty list of array. So if

os_filter_val = request.query_params.getlist('osFilter[]')
server_owner_list = request.query_params.getlist('serverOwnerFilter[]')      
Server.Objects.filter(
                os__in=os_filter_val,
                server_owner__in=server_owner_list)

So in the above example consider for server_owner_list I got an empty array and I don't want to include it in the filter queryset what I would generally do is.

if len(os_filter_val) > 0 and len(server_owner_list) > 0:
    Server.Objects.filter(
                os__in=os_filter_val,
                server_owner__in=server_owner_list)
else if(os_filter_val) > 0 and len(server_ownder_list) == 0:
    Server.Objects.filter(os__in=os_filter_val)
....
....
....

So here if fields are more then I have to write a lot of if-else condition to check whether there are any empty lists. If its there do not include it in the queryset.

So is there any way where we can check for the empty list and add only the nonempty lists without writing the if-else conditions.

Try this code.Change OR and AND as per your requirement and also add if condition in your url parameters.

from django.db.models import Q
    os_filter_val = request.query_params.getlist('osFilter[]')
        server_owner_list = request.query_params.getlist('serverOwnerFilter[]')
        q_objects = Q()
        if os_filter_val:
            q_objects.add(Q(os__in=os_filter_val), Q.OR)
        if server_owner_list:
            q_objects.add(Q(server_owner__in=server_owner_list), Q.OR)
        Server.Objects.filter(q_objects,)

For filtering, in general, I recommend you Django-Filters. It will save you a lot of if-else conditions. For specific in filter, you can write a custom filter class:

from rest_framework import generics
from django_filters import rest_framework as filters
from myapp import Server


class ServerFilter(filters.FilterSet):
    osFilter = filters.NumberFilter(field_name="id", lookup_expr='in')

    class Meta:
        model = Server
        fields = ['osFilter',]


class ServerList(generics.ListAPIView):
    queryset = Server.objects.all()
    serializer_class = ServerSerializer
    filter_backends = (filters.DjangoFilterBackend,)
    filterset_class = ServerFilter

But besides that I recommend you to read about some tips with in null and ranges and base filtering