feat: SAP unique on (active, assignment_configuration)

enterprise_access/apps/subsidy_access_policy/migrations/0017_active_assignment_config_unique.py

@@ -0,0 +1,22 @@
+# Generated by Django 3.2.20 on 2023-09-11 19:25
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('content_assignments', '0003_drop_assignment_policy'),
+        ('subsidy_access_policy', '0016_assignment_config_fk'),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='subsidyaccesspolicy',
+            options={},
+        ),
+        migrations.AlterUniqueTogether(
+            name='subsidyaccesspolicy',
+            unique_together={('active', 'assignment_configuration')},
+        ),
+    ]

enterprise_access/apps/subsidy_access_policy/models.py

@@ -58,6 +58,11 @@ class SubsidyAccessPolicy(TimeStampedModel):
     .. no_pii: This model has no PII
     """
 
+    class Meta:
+        unique_together = [
+            ('active', 'assignment_configuration'),
+        ]
+
     POLICY_FIELD_NAME = 'policy_type'
     policy_type = models.CharField(
         max_length=64,
@@ -159,7 +164,6 @@ class SubsidyAccessPolicy(TimeStampedModel):
         related_name='subsidy_access_policy',
         on_delete=models.SET_NULL,
         db_index=True,
-        unique=True,
         null=True,
     )