Question

让我们说我有以下问题：

SELECT to_char(request_date,'YYYY-MM-DD HH24:MI:SS') date_time
  FROM tableA;

输出类似于：

date_time
-------------------------
2015-12-19 11:27:57

现在，我想选择时间戳为00:00:00，无论它实际是什么时间戳。我怎样才能做到这一点？我的意思是我想得到如下结果：

date_time
-------------------------
2015-12-19 00:00:00

请指教。谢谢！

Answer 1

最简单的方法是截断日期：

    Calendar today = Calendar.getInstance();
    today.set(HOUR_OF_DAY, 0);
    today.set(MINUTE, 0);
    today.set(SECOND, 0);
    today.set(MILLISECOND, 0);

    Calendar date = Calendar.getInstance();
    date.setTime(formatter.parse(LastUpdate));
    date.set(HOUR_OF_DAY, 0);
    date.set(MINUTE, 0);
    date.set(SECOND, 0);
    date.set(MILLISECOND, 0);

    today.compareTo(date)

选择时间戳为00:00:00

1 个答案: