Klass.name must be unique

stages/migrations/0021_klass_name_unique.py

@@ -0,0 +1,21 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stages', '0020_remove_old_ext_id'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='klass',
+            name='name',
+            field=models.CharField(max_length=10, unique=True, verbose_name='Nom'),
+        ),
+        migrations.AlterField(
+            model_name='student',
+            name='klass',
+            field=models.ForeignKey(blank=True, null=True, on_delete=models.deletion.PROTECT, to='stages.Klass', verbose_name='Classe'),
+        ),
+    ]