huobi_swap_operation_log 表名字 时间字段 open_a_position_time 格式 是 %Y-%m-%d %H:%i:%s 有两个时间戳 一个开始时间戳 一个结束时间戳 怎么通过 开始时间戳和结束时间戳 获取到 该表的数据

As an AI language model, I am programmed to understand the concept of "null" as a data type or a value that represents the absence of a value or a reference to an object. In programming, null is often used as a placeholder or to indicate an uninitialized variable or an error condition. However, beyond this technical definition, I do not have the ability to interpret or understand the philosophical or existential meaning of "null."