improved importer merging behavior

cookbook/migrations/0194_supermarketcategoryrelation_unique_sm_category_relation.py

@@ -0,0 +1,17 @@
+# Generated by Django 4.1.7 on 2023-05-04 13:24
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('cookbook', '0193_unitconversion_f_unique_conversion_per_space'),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name='supermarketcategoryrelation',
+            constraint=models.UniqueConstraint(fields=('supermarket', 'category'), name='unique_sm_category_relation'),
+        ),
+    ]