1 files changed, 15 insertions, 6 deletions
diff --git a/archaeological_context_records/models.py b/archaeological_context_records/models.py
index a5608c8d0..df6d22ff2 100644
--- a/archaeological_context_records/models.py
+++ b/archaeological_context_records/models.py
@@ -25,10 +25,10 @@ from django.conf import settings
 from django.contrib.gis.db import models
 from django.contrib.gis.geos import Point
 from django.contrib.postgres.indexes import GinIndex
-from django.core.urlresolvers import reverse
 from django.db import connection
 from django.db.models import Q
 from django.db.models.signals import post_delete, post_save, m2m_changed
+from django.urls import reverse
 
 from ishtar_common.utils import ugettext_lazy as _, pgettext_lazy, pgettext
 from django.utils.text import slugify
@@ -100,7 +100,9 @@ post_delete.connect(post_save_cache, sender=DatingQuality)
 
 class Dating(models.Model):
     uuid = models.UUIDField(default=uuid.uuid4)
-    period = models.ForeignKey(Period, verbose_name=_("Period"))
+    period = models.ForeignKey(
+        Period, verbose_name=_("Period"), on_delete=models.PROTECT
+    )
     start_date = models.IntegerField(_("Start date"), blank=True, null=True)
     end_date = models.IntegerField(_("End date"), blank=True, null=True)
     dating_type = models.ForeignKey(
@@ -638,7 +640,10 @@ class ContextRecord(
         null=True,
     )
     operation = models.ForeignKey(
-        Operation, verbose_name=_("Operation"), related_name="context_record"
+        Operation,
+        verbose_name=_("Operation"),
+        related_name="context_record",
+        on_delete=models.CASCADE,
     )
     archaeological_site = models.ForeignKey(
         ArchaeologicalSite,
@@ -1222,9 +1227,13 @@ class RecordRelationsManager(models.Manager):
 
 class RecordRelations(GeneralRecordRelations, models.Model):
     MAIN_ATTR = "left_record"
-    left_record = models.ForeignKey(ContextRecord, related_name="right_relations")
-    right_record = models.ForeignKey(ContextRecord, related_name="left_relations")
-    relation_type = models.ForeignKey(RelationType)
+    left_record = models.ForeignKey(
+        ContextRecord, related_name="right_relations", on_delete=models.CASCADE
+    )
+    right_record = models.ForeignKey(
+        ContextRecord, related_name="left_relations", on_delete=models.CASCADE
+    )
+    relation_type = models.ForeignKey(RelationType, on_delete=models.PROTECT)
     objects = RecordRelationsManager()
     TABLE_COLS = [
         "left_record__label",