feat(dnd-worldmap-removal) Added null checks for columns and fields. (#…

…53475)

- Migration already approved here:
[PR](#53109) but it had a
runtime error.
- Added null checks for columns and fields in DashboardWidgetQuery.
- Should fix run time error from previous migration attempt: 
<img width="488" alt="Screenshot 2023-07-24 at 6 17 48 PM"
src="https://github.com/getsentry/sentry/assets/60121741/49fe3214-77c3-4bdb-b02f-355eb567f1d3">

- Link to failure:
https://deploy.getsentry.net/go/tab/build/detail/deploy-getsentry-backend-us/63/migrations/1/migrations
- Tested it out locally with NULL columns.

Co-authored-by: Abdullah Khan <abdullahkhan@PG9Y57YDXQ.local>

migrations_lockfile.txt

@@ -6,5 +6,5 @@ To resolve this, rebase against latest master and regenerate your migration. Thi
 will then be regenerated, and you should be able to merge without conflicts.
 
 nodestore: 0002_nodestore_no_dictfield
-sentry: 0520_add_flat_file_index_table
+sentry: 0521_migrate_world_map_widgets
 social_auth: 0002_default_auto_field

src/sentry/migrations/0521_migrate_world_map_widgets.py

@@ -0,0 +1,66 @@
+# Generated by Django 3.2.20 on 2023-07-25 13:35
+
+from django.db import migrations
+
+from sentry.models import DashboardWidgetQuery
+from sentry.new_migrations.migrations import CheckedMigration
+
+
+def migrate_worldmap_widgets_to_table_widgets(apps, schema_editor):
+    # World map visulization has display_type 5
+    widgetQueries = DashboardWidgetQuery.objects.select_related("widget").filter(
+        widget__display_type=5
+    )
+
+    for widgetQuery in widgetQueries:
+        # Change widget display type from world_map:5 to table:4
+        widgetQuery.widget.display_type = 4
+
+        # Ensure condition has country_code check
+        if "has:geo.country_code" not in widgetQuery.conditions:
+            widgetQuery.conditions = widgetQuery.conditions + " has:geo.country_code"
+
+        # Add region and country_code columns
+        if not widgetQuery.columns:
+            widgetQuery.columns = []
+        if "geo.region" not in widgetQuery.columns:
+            widgetQuery.columns.insert(0, "geo.region")
+        if "geo.country_code" not in widgetQuery.columns:
+            widgetQuery.columns.insert(0, "geo.country_code")
+
+        # Add region and country_code as fields
+        if not widgetQuery.fields:
+            widgetQuery.fields = []
+        if "geo.region" not in widgetQuery.fields:
+            widgetQuery.fields.insert(0, "geo.region")
+        if "geo.country_code" not in widgetQuery.fields:
+            widgetQuery.fields.insert(0, "geo.country_code")
+
+        widgetQuery.widget.save()
+        widgetQuery.save()
+
+
+class Migration(CheckedMigration):
+    # This flag is used to mark that a migration shouldn't be automatically run in production. For
+    # the most part, this should only be used for operations where it's safe to run the migration
+    # after your code has deployed. So this should not be used for most operations that alter the
+    # schema of a table.
+    # Here are some things that make sense to mark as dangerous:
+    # - Large data migrations. Typically we want these to be run manually by ops so that they can
+    #   be monitored and not block the deploy for a long period of time while they run.
+    # - Adding indexes to large tables. Since this can take a long time, we'd generally prefer to
+    #   have ops run this and not block the deploy. Note that while adding an index is a schema
+    #   change, it's completely safe to run the operation after the code has deployed.
+    is_dangerous = True
+
+    dependencies = [
+        ("sentry", "0520_add_flat_file_index_table"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            migrate_worldmap_widgets_to_table_widgets,
+            migrations.RunPython.noop,
+            hints={"tables": ["sentry_dashboardwidgetquery", "sentry_dashboardwidget"]},
+        ),
+    ]