code: def _get_column_names_in_altered_table(self, diff):
          
          columns = OrderedDict()
  
          for column_name, column in diff.from_table.get_columns().items():
              columns[column_name.lower()] = column.get_name()
  
          for column_name, column in diff.removed_columns.items():
              column_name = column_name.lower()
              if column_name in columns:
                  del columns[column_name]
  
          for old_column_name, column in diff.renamed_columns.items():
              column_name = column.get_name()
              columns[old_column_name.lower()] = column_name
              columns[column_name.lower()] = column_name
  
          for old_column_name, column_diff in diff.changed_columns.items():
              column_name = column_diff.column.get_name()
              columns[old_column_name.lower()] = column_name
              columns[column_name.lower()] = column_name
  
          for column_name, column in diff.added_columns.items():
              columns[column_name.lower()] = column_name
  
          return columns
docs: :param diff: The table diff
          :type diff: orator.dbal.table_diff.TableDiff
  
          :rtype: dict