Add migration

Author: stsewd

readthedocs/projects/migrations/0024_auto_20171229_1546.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.16 on 2018-11-01 20:55
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+from django.db.models.functions import Length
+
+
+def forwards_func(apps, schema_editor):
+    max_length = 63
+    Project = apps.get_model('projects', 'Project')
+    projects_invalid_slug = (
+        Project
+        .objects
+        .annotate(slug_length=Length('slug'))
+        .filter(slug_length__gt=max_length)
+    )
+    for project in projects_invalid_slug:
+        project.slug = project.slug[:max_length]
+        project.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('projects', '0029_add_additional_languages'),
+    ]
+
+    operations = [
+        migrations.RunPython(forwards_func),
+        migrations.AlterField(
+            model_name='project',
+            name='slug',
+            field=models.SlugField(max_length=63, unique=True, verbose_name='Slug'),
+        ),
+    ]