feat: 增加drain2serializer返回数据

apps/enp/serializers.py

@@ -24,6 +24,7 @@ class DrainSerializer(CustomModelSerializer):
 
 class Drain2Serializer(CustomModelSerializer):
     equip_data = serializers.SerializerMethodField()
+    mgroup_name = serializers.CharField(source='mgroup.name', read_only=True)
 
     class Meta:
         model = Drain

apps/enp/views.py

@@ -21,6 +21,7 @@ class DrainViewSet(CustomModelViewSet):
     queryset = Drain.objects.all()
     serializer_class = DrainSerializer
     filterset_fields = ['type', 'cate', 'mgroup']
+    select_related_fields = ['mgroup']
 
     def get_serializer_class(self):
         has_equipdata = self.request.query_params.get('has_equipdata', 'no')