set unique constraint on parameter

Author: aperrin66

geospaas/vocabularies/migrations/0013_parameter_unique_parameter.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.2.25 on 2025-05-20 09:17
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('vocabularies', '0012_auto_20250514_0542'),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name='parameter',
+            constraint=models.UniqueConstraint(fields=('version', 'kind', 'data'), name='unique_parameter'),
+        ),
+    ]

geospaas/vocabularies/models.py

@@ -54,3 +54,8 @@ def __str__(self):
 
     def natural_key(self):
         return (self.data['standard_name'])
+
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(name='unique_parameter', fields=('version', 'kind', 'data'))
+        ]