oracle systimestamp (sysdate) to milliseconds

Question

Could you provide implementation of stored function to get current systimestamp as milliseconds.
Something I can use like

select current_tim         


        

Answer 1

• DB timezone agnostic
• with milliseconds
• works in 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

I've posted here some methods to convert timestamp to nanoseconds and nanoseconds to timestamp. These methods are not affected by time zones and have a nanosecond precision.

You just need to adjust it to get milliseconds instead of nanoseconds.

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 3

AFAIK, there is no direct way for achieving this (other than manually writing a long-winded SQL function).

Why do you need this specifically?

You could use a stored Java function and then use the System.getCurrentMillis() that Java provides to return you a value in Milliseconds from 1.1.1970 to now.

Answer 4

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

Answer 5

Below code gives the difference in milliseconds:

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

For conversion of milliseconds to Hours, Minutes, seconds, modify and use below query as appropriate:

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

Adding to @Mykhaylo Adamovych answer (which looks correct!) here goes a more straightforward approach using oracle Java support (i.e. not in XE and not in AWS RDS). Less portable (in case you care), but seemed faster in my testing.

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