code: def compile_change(self, blueprint, command, connection):
          
          schema = connection.get_schema_manager()
  
          table_diff = self._get_changed_diff(blueprint, schema)
  
          if table_diff:
              sql = schema.get_database_platform().get_alter_table_sql(table_diff)
  
              if isinstance(sql, list):
                  return sql
  
              return [sql]
  
          return []
docs: Compile a change column command into a series of SQL statement.
  
          :param blueprint: The blueprint
          :type blueprint: Blueprint
  
          :param command: The command
          :type command: Fluent
  
          :param connection: The connection
          :type connection: orator.connections.Connection
  
          :rtype: list