CablePath.origin should be unique

netbox/dcim/migrations/0120_cablepath.py

@@ -1,3 +1,5 @@
+# Generated by Django 3.1 on 2020-10-02 15:49
+
 import dcim.fields
 from django.db import migrations, models
 import django.db.models.deletion
@@ -18,9 +20,12 @@ class Migration(migrations.Migration):
                 ('origin_id', models.PositiveIntegerField()),
                 ('destination_id', models.PositiveIntegerField(blank=True, null=True)),
                 ('path', dcim.fields.PathField(base_field=models.CharField(max_length=40), size=None)),
+                ('is_connected', models.BooleanField(default=False)),
                 ('destination_type', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='+', to='contenttypes.contenttype')),
                 ('origin_type', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='+', to='contenttypes.contenttype')),
-                ('is_connected', models.BooleanField(default=False)),
             ],
+            options={
+                'unique_together': {('origin_type', 'origin_id')},
+            },
         ),
     ]

netbox/dcim/models/devices.py

@@ -1197,6 +1197,9 @@ class CablePath(models.Model):
 
     objects = CablePathManager()
 
+    class Meta:
+        unique_together = ('origin_type', 'origin_id')
+
     def __str__(self):
         path = ', '.join([str(path_node_to_object(node)) for node in self.path])
         return f"Path #{self.pk}: {self.origin} to {self.destination} via ({path})"