text: 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),
      ]
  