se optimiza consulta de rutas de mapa

project/api/views/mapa.py

@@ -2,6 +2,9 @@
 from django.http import JsonResponse
 from rest_framework.decorators import action, api_view, schema
 from django.views.decorators.csrf import csrf_exempt
+from django.db.models import F, Subquery, Value
+from django.db.models.functions import Coalesce
+
 from ..models import Paradero, ParaderoImagen
 from ..models import Linea, GtfsShape, GtfsTrips
 from .paradero import url_image_paradero
@@ -45,19 +48,18 @@ def paraderos(request):
 def rutas(request):
     id_linea = request.GET.get('id_linea')
 
-    sectores = GtfsTrips.objects.filter(id_linea = id_linea).all()
+    # Subquery para obtener los id_shape distintos de gtfs_trips
-    data = []
+    subquery = GtfsTrips.objects.filter(id_linea = id_linea).values('id_shape').distinct()
-    for s in sectores:
+
-        rutas = GtfsShape.objects.filter(id_shape = s.id_shape).order_by('shape_pt_sequence')
+    # Consulta principal con inner join y ordenamiento
-        for r in rutas:
+    queryset = GtfsShape.objects.annotate(
-            data.append({
+        id_shape_subquery=Subquery(subquery),
-              'shape_pt_lat': r.shape_pt_lat,
+        shape_pt_sequence_coalesce=Coalesce('shape_pt_sequence', Value(0))
-              'shape_pt_lon': r.shape_pt_lon,
+    ).filter(id_shape=F('id_shape_subquery')).order_by('shape_pt_sequence_coalesce')
-              'shape_pt_sequence': r.shape_pt_sequence
+
-            })
+    result = queryset.values('shape_pt_lat', 'shape_pt_lon', 'shape_pt_sequence')
-    data_ordenada = sorted(data, key=lambda k: k['shape_pt_sequence'])
 
     return JsonResponse({
         'google_api_key': google_api_key,
-        'positions': data_ordenada
+        'positions': list(result)
     })