Add a UniqueConstraint to prevent duplicates.

https://github.com/python-discord/site/issues/305

2 files changed, 21 insertions, 0 deletions

diff --git a/pydis_site/apps/api/migrations/0057_allowlist.py b/pydis_site/apps/api/migrations/0057_create_new_allowlist_model.py
index 7d815e91..45650d86 100644
--- a/pydis_site/apps/api/migrations/0057_allowlist.py
+++ b/pydis_site/apps/api/migrations/0057_create_new_allowlist_model.py
@@ -26,4 +26,12 @@ class Migration(migrations.Migration):
             },
             bases=(pydis_site.apps.api.models.mixins.ModelReprMixin, models.Model),
         ),
+        migrations.AlterModelTable(
+            name='allowlist',
+            table='allow_list',
+        ),
+        migrations.AddConstraint(
+            model_name='allowlist',
+            constraint=models.UniqueConstraint(fields=('content', 'type'), name='unique_allowlist'),
+        )
     ]
diff --git a/pydis_site/apps/api/models/bot/allowlist.py b/pydis_site/apps/api/models/bot/allowlist.py
index b0aea066..fc57ef32 100644
--- a/pydis_site/apps/api/models/bot/allowlist.py
+++ b/pydis_site/apps/api/models/bot/allowlist.py
@@ -24,3 +24,16 @@ class AllowList(ModelTimestampMixin, ModelReprMixin, models.Model):
     content = models.TextField(
         help_text="The data to add to the allowlist."
     )
+
+    class Meta:
+        """Metaconfig for this model."""
+
+        db_table = 'allow_list'
+
+        # This constraint ensures only one allowlist with the same content
+        # can exist per type.This means that we cannot have both an allow
+        # and a deny for the same item, and we cannot have duplicates of the
+        # same item.
+        constraints = [
+            models.UniqueConstraint(fields=['content', 'type'], name='unique_allowlist'),
+        ]