Question

你能提供存储函数的实现来获得当前的systimestamp毫秒数我可以使用的东西，如

select current_time_ms from dual;

并获得当前时间与1970年1月1日午夜时间之间的差异（以毫秒为单位）。

感谢。

Answer 1

DB timezone agnostic
毫秒
适用于XE

    function current_time_ms
        return number
    is
        out_result number;
    begin
        select extract(day from(sys_extract_utc(systimestamp) - to_timestamp('1970-01-01', 'YYYY-MM-DD'))) * 86400000 
            + to_number(to_char(sys_extract_utc(systimestamp), 'SSSSSFF3'))
        into out_result
        from dual;
        return out_result;
    end current_time_ms;

Answer 2

我所知道的最好的事情是：

select extract(day    from (systimestamp - timestamp '1970-01-01 00:00:00')) * 86400000
     + extract(hour   from (systimestamp - timestamp '1970-01-01 00:00:00')) * 3600000
     + extract(minute from (systimestamp - timestamp '1970-01-01 00:00:00')) * 60000
     + extract(second from (systimestamp - timestamp '1970-01-01 00:00:00')) * 1000 unix_time
from dual;

我不太确定您对时区有什么要求。您可能需要对此进行微调。

Answer 3

添加到@Mykhaylo Adamovych的答案（看起来正确！）这里使用oracle Java支持（即不在XE而不在AWS RDS中）是一种更简单的方法。不太便携（如果你关心的话），但在我的测试中似乎更快。

CREATE or replace FUNCTION current_java_timestamp RETURN number
AS LANGUAGE JAVA NAME 'java.lang.System.currentTimeMillis() return java.lang.Long';
/

Answer 4

AFAIK，没有直接的方法来实现这一点（除了手动编写冗长的SQL函数）。

为什么你需要这个？

您可以使用存储的Java函数，然后使用Java提供的System.getCurrentMillis（）来返回从1.1.1970到现在的毫秒数值。

Answer 5

下面的代码给出了以毫秒为单位的差异：

with t as (select systimestamp - to_timestamp(sysdate ) diff from dual)
select extract(day from diff) * 24 * 3600000+
   extract(hour from diff) * 3600000+
   extract(minute from diff) * 60000 +
   extract(second from diff) * 1000  
    dif
from t

将毫秒转换为小时，分钟，秒，根据需要修改和使用以下查询：

with t as (select systimestamp - to_timestamp(sysdate ) diff from dual)
select extract(day from diff) * 24 * 3600000+
   extract(hour from diff) * 3600000+
   extract(minute from diff) * 60000 +
   extract(second from diff) * 1000  
    dif,
    (to_char (to_date(round(( extract(day from diff) * 24 * 3600000+
   extract(hour from diff) * 3600000+
   extract(minute from diff) * 60000 +
   extract(second from diff) * 1000)/1000), 'SSSSS' ), 'HH24"Hrs" MI"Min" SS"Sec"'))  timeval
from t

Answer 6

我已经发布了here一些将时间戳转换为纳秒和将纳秒转换为时间戳的方法。这些方法不受时区的影响，并且具有纳秒级的精度。

您只需将其调整为毫秒而不是纳秒。

SELECT (EXTRACT(DAY FROM (
    SYSTIMESTAMP --Replace line with desired timestamp --Maximum value: TIMESTAMP '3871-04-29 10:39:59.999999999 UTC'
- TIMESTAMP '1970-01-01 00:00:00 UTC') * 24 * 60) * 60 + EXTRACT(SECOND FROM
    SYSTIMESTAMP --Replace line with desired timestamp
)) *  1000 AS MILLIS FROM DUAL;

MILLIS
1598434427263.027

Answer 7

SELECT to_char(sysdate, 'HH24:MI:SS'), to_char(systimestamp, 'HH24:MI:SS.FF6') FROM dual

oracle systimestamp（sysdate）到毫秒

7 个答案: