# Generated by Django 1.11.18 on 2019-02-25 12:42 from django.db import migrations from django.db.backends.base.schema import BaseDatabaseSchemaEditor from django.db.migrations.state import StateApps def backfill_first_message_id(apps: StateApps, schema_editor: BaseDatabaseSchemaEditor) -> None: Stream = apps.get_model("zerver", "Stream") Message = apps.get_model("zerver", "Message") for stream in Stream.objects.all(): first_message = Message.objects.filter( recipient__type_id=stream.id, recipient__type=2 ).first() if first_message is None: # No need to change anything if the outcome is the default of None continue stream.first_message_id = first_message.id stream.save() class Migration(migrations.Migration): dependencies = [ ("zerver", "0209_stream_first_message_id"), ] operations = [ migrations.RunPython( backfill_first_message_id, reverse_code=migrations.RunPython.noop, elidable=True ), ]