[PATCH] Optimize slug duplication migration

Author: PetrDlouhy

categories/migrations/0005_unique_category_slug.py

@@ -2,20 +2,23 @@
 
 from django.db import migrations, models
 
+from categories.models import Category
+
 
 def make_slugs_unique(apps, schema_editor):
-    Category = apps.get_model("categories", "Category")
     duplicates = Category.tree.values("slug").annotate(slug_count=models.Count("slug")).filter(slug_count__gt=1)
+    category_objs = []
     for duplicate in duplicates:
         slug = duplicate["slug"]
         categories = Category.tree.filter(slug=slug)
         count = categories.count()
         i = 0
         for category in categories.all():
             if i != 0:
-                category.slug = "%s_%s" % (slug, str(i).zfill(len(str(count))))
-                category.save()
+                category.slug = "{}-{}".format(slug, str(i).zfill(len(str(count))))
+                category_objs.append(category)
             i += 1
+    Category.objects.bulk_update(category_objs, ["slug"])
 
 
 class Migration(migrations.Migration):

categories/tests/test_migrations.py

@@ -25,19 +25,19 @@ def test_unique_slug_migration(self):
                 list(Category.tree.values_list("slug", flat=True)),
                 [
                     "foo",
-                    "foo_1",
-                    "foo_2",
+                    "foo-1",
+                    "foo-2",
                     "bar",
-                    "bar_01",
-                    "bar_02",
-                    "bar_03",
-                    "bar_04",
-                    "bar_05",
-                    "bar_06",
-                    "bar_07",
-                    "bar_08",
-                    "bar_09",
-                    "bar_10",
+                    "bar-01",
+                    "bar-02",
+                    "bar-03",
+                    "bar-04",
+                    "bar-05",
+                    "bar-06",
+                    "bar-07",
+                    "bar-08",
+                    "bar-09",
+                    "bar-10",
                     "baz",
                 ],
             )