fix - if rancher duplicated in check with national code in pos

apps/herd/pos/api/v1/api.py

@@ -1,15 +1,17 @@
-from apps.herd.pos.api.v1.serializers import HerdSerializer, RancherSerializer
-from apps.livestock.web.api.v1.serializers import LiveStockSerializer
-from apps.core.mixins.search_mixin import DynamicSearchMixin
+from django.db import transaction
+from rest_framework import status
+from rest_framework import viewsets
+from rest_framework.decorators import action
 from rest_framework.exceptions import APIException
 from rest_framework.permissions import AllowAny
 from rest_framework.response import Response
-from rest_framework.decorators import action
-from common.tools import CustomOperations
-from rest_framework import viewsets
+
+from apps.core.mixins.search_mixin import DynamicSearchMixin
+from apps.herd.exception import DuplicateRancherException
 from apps.herd.models import Herd, Rancher
-from django.db import transaction
-from rest_framework import status
+from apps.herd.pos.api.v1.serializers import HerdSerializer, RancherSerializer
+from apps.livestock.web.api.v1.serializers import LiveStockSerializer
+from common.tools import CustomOperations
 
 
 class HerdViewSet(viewsets.ModelViewSet):
@@ -139,6 +141,9 @@ class RancherViewSet(viewsets.ModelViewSet, DynamicSearchMixin):
 
         rancher = self.queryset.filter(national_code=request.data['national_code'])
 
+        if len(rancher) > 1:
+            raise DuplicateRancherException()
+
         if rancher.exists():
             serializer = self.serializer_class(rancher.first())
             return Response(serializer.data, status=status.HTTP_200_OK)