Add unique constraint to followers relationship. #47

fedireads/migrations/0007_auto_20200223_0902.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.0.3 on 2020-02-23 09:02
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('fedireads', '0006_auto_20200221_1702'),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name='userrelationship',
+            constraint=models.UniqueConstraint(fields=('user_subject', 'user_object'), name='followers_unique'),
+        ),
+    ]

fedireads/models/user.py

@@ -73,6 +73,11 @@ class UserRelationship(FedireadsModel):
     status = models.CharField(max_length=100, default='follows', null=True)
     relationship_id = models.CharField(max_length=100)
 
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(fields=['user_subject', 'user_object'], name='followers_unique')
+        ]
+
     @property
     def absolute_id(self):
         ''' use shelf identifier as absolute id '''