diff --git a/transport_accessibility/pt_map/migrations/0003_faretransferrule_feed_info_id.py b/transport_accessibility/pt_map/migrations/0003_faretransferrule_feed_info_id.py
index 335d33d..e9d8112 100644
--- a/transport_accessibility/pt_map/migrations/0003_faretransferrule_feed_info_id.py
+++ b/transport_accessibility/pt_map/migrations/0003_faretransferrule_feed_info_id.py
@@ -15,7 +15,7 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='faretransferrule',
             name='feed_info_id',
-            field=models.ForeignKey(default=django.utils.timezone.now, on_delete=django.db.models.deletion.CASCADE, to='pt_map.feedinfo'),
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='pt_map.feedinfo'),
             preserve_default=False,
         ),
     ]
diff --git a/transport_accessibility/pt_map/views.py b/transport_accessibility/pt_map/views.py
index a243f29..db7a86f 100644
--- a/transport_accessibility/pt_map/views.py
+++ b/transport_accessibility/pt_map/views.py
@@ -13,6 +13,7 @@ from django.http import HttpResponse, HttpResponseBadRequest, HttpResponseNotAll
 from django.core.exceptions import BadRequest, ObjectDoesNotExist
 from django.core import serializers
 import django.db.models
+from MySQLdb import IntegrityError
 from .models import *
 from .forms import *
 import json
@@ -133,23 +134,47 @@ def data(request):
         Successful response is 200 with a list of the primary keys of the modified objects.
     GET
         Return json of models identified by primary keys.
+        Responds 400 if any of the requested pks does not exist.
     DELETE
         Delete models with given primary keys if they exist.
         Responds 400 if any of the primary keys given does not exist in the database.
         Successful response is 200 and the number of deleted models.
     """
-    if request.method == "PUT":
+    if request.method in ["PUT", "PATCH", "DELETE"]:
+        new = 0
+        modified = 0
         if not request.META["CONTENT_TYPE"] == 'application/json':
             HttpResponseBadRequest('Request must be JSON.')
         try:
-            bdy = json.loads(request.body)
+            for o in serializers.deserialize('json', request.body):
+                try:
+                    obj = o.object.__class__.objects.get(pk=o.object.pk)
+                    modified += 1
+                    if request.method == "PATCH":
+                        for f,v in o.object.__dict__.items():
+                            if v:
+                                setattr(obj, f, v)
+                        obj.save()
+                    else:
+                        obj.delete()
+                        if request.method == "PUT":
+                            o.save()
+                except ObjectDoesNotExist:
+                    if not request.method == "PUT":
+                        return HttpResponseBadRequest("Object(s) not found. {modified} objects touched.")
+                    new += 1
+                    o.save()
+        except django.db.IntegrityError:
+            return HttpResponseBadRequest("Could not write to database. Probably the objects you were trying to create or update where not compliant with GTFS's or the API's specification.")
+        except IntegrityError:
+            return HttpResponseBadRequest("There was an error while trying to write to the database. Probably a foreign key could not be resolved. Did you specify the objects in the correct order, if they depend on each other?")
+        except serializers.base.DeserializationError:
+            return HttpResponseBadRequest("Could not process the JSON you sent me correctly. Did you comply with the format required by the API and used valid JSON?")
         except json.JSONDecodeError:
-            return HttpResponseBadRequest("Malformed json.")
-        return HttpResponse(f"received {obj}")
-    elif request.method == "PATCH":
-        if not request.META["CONTENT_TYPE"] == 'application/json':
-            HttpResponseBadRequest('Request must be JSON.')
-        return HttpResponse(f"received {obj}")
+            return HttpResponseBadRequest("Invalid JSON.")
+        except django.db.utils.DataError:
+            return HttpResponseBadRequest("One of your objects has fields that do not fit in their corresponding fields in the database. Did you comply to all data type requirements?")
+        return HttpResponse(f"OK. {new} new objects, {modified} replaced.") if request.method == "PUT" else HttpResponse(f"OK. {'Patched' if request.method == 'PATCH' else 'Deleted'} {modified} objects.")
     elif request.method == "GET":
         try:
             pks = get_pks_from_get(request.GET)