From 06b547057e5822bfdff1272c1f8209f12c66bf2a Mon Sep 17 00:00:00 2001
From: Troy Sankey <tsankey@edx.org>
Date: Fri, 28 Feb 2020 11:31:39 -0500
Subject: [PATCH] Add migration to populate site_values in
 SiteConfigurationHistory

Right now the ORM is very unhappy about the JSONField `site_values`
in SiteConfigurationHistory containing non-JSON (empty strings).  We
cannot even write a data migration using the ORM to populate the field
because that causes a JSONDeserializationError.  Therefore, we must
bypass the ORM and populate the values with raw SQL.

DENG-18
---
 ...populate_siteconfig_history_site_values.py | 29 +++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 openedx/core/djangoapps/site_configuration/migrations/0005_populate_siteconfig_history_site_values.py

diff --git a/openedx/core/djangoapps/site_configuration/migrations/0005_populate_siteconfig_history_site_values.py b/openedx/core/djangoapps/site_configuration/migrations/0005_populate_siteconfig_history_site_values.py
new file mode 100644
index 0000000000..b117380d5b
--- /dev/null
+++ b/openedx/core/djangoapps/site_configuration/migrations/0005_populate_siteconfig_history_site_values.py
@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+forward_sql = """
+UPDATE
+    site_configuration_siteconfigurationhistory
+SET
+    site_values = '{}';
+"""
+
+reverse_sql = """
+UPDATE
+    site_configuration_siteconfigurationhistory
+SET
+    site_values = '';
+"""
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('site_configuration', '0004_add_site_values_field'),
+    ]
+
+    operations = [
+        migrations.RunSQL(forward_sql, reverse_sql=reverse_sql),
+    ]