Add temporary ext_id_old for Corporation and CorpContact

stages/migrations/0019_add_old_ext_id.py

@@ -0,0 +1,31 @@
+from django.db import migrations, models
+
+
+def migrate_extid(apps, schema_editor):
+    Corporation = apps.get_model("stages", "Corporation")
+    CorpContact = apps.get_model("stages", "CorpContact")
+    Corporation.objects.update(ext_id_old=models.F('ext_id'))
+    CorpContact.objects.update(ext_id_old=models.F('ext_id'))
+    Corporation.objects.update(ext_id=None)
+    CorpContact.objects.update(ext_id=None)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stages', '0018_removed_referent_model'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='corpcontact',
+            name='ext_id_old',
+            field=models.IntegerField(blank=True, null=True, verbose_name='ID externe (ancien)'),
+        ),
+        migrations.AddField(
+            model_name='corporation',
+            name='ext_id_old',
+            field=models.IntegerField(blank=True, null=True, verbose_name='ID externe (ancien)'),
+        ),
+        migrations.RunPython(migrate_extid, migrations.RunPython.noop),
+    ]