is there any way in Oracle, to get only the dd-mm-yyyy part from an unix timestamp in oracle?
Like:
select to_char(my_timestamp, 'ddmmyyyy') as my_new_timestamp from table
Given this data ...
SQL> alter session set nls_date_format='dd-mon-yyyy hh24:mi:ss'
2 /
Session altered.
SQL> select * from t23
2 /
MY_TIMESTAMP
--------------------
08-mar-2010 13:06:02
08-mar-2010 13:06:08
13-mar-1985 13:06:26
SQL>
.. it is simply a matter of converting the time elapsed since 01-JAN-1970 into seconds:
SQL> select my_timestamp
2 , (my_timestamp - date '1970-01-01') * 86400 as unix_ts
3 from t23
4 /
MY_TIMESTAMP UNIX_TS
-------------------- ----------
08-mar-2010 13:06:02 1268053562
08-mar-2010 13:06:08 1268053568
13-mar-1985 13:06:26 479567186
SQL>
As I understand it, A Unix timestamp is defined as a number of seconds since 1970-01-01, in which case:
select DATE '1970-01-01' + my_timestamp/86400 from table;
(There are 86400 seconds in a day.)
To ignore the hours, minutes and seconds:
select TRUNC(DATE '1970-01-01' + my_timestamp/86400) from table;
However, if what you want is a "truncated" Unix timestamp then try this:
select floor(my_timestamp/84600)*84600 from dual;
I believe it's:
select to_char(my_timestamp, 'dd-mm-yyyy') as my_new_timestamp from table
See also this reference on Oracle's date format specifiers.
Unix timestamp is seconds since Jan 01 1970. (UTC).
To get Unix timestamp of now, try the follwing sql:
select (CAST(SYS_EXTRACT_UTC(current_timestamp) AS date) - to_date('1970-01-01', 'YYYY-MM-DD')) * 86400 FROM dual;
You can replace current_timestamp with any timestamp-value.
BTW, some answers seem to return seconds since Jan 01, 1970 with local time zone. That's wrong.
Related
While trying to convert datetime to epoch, I am getting an error: ORA-01810: format code appears twice
QracleSQL query:
select (trunc(TO_TIMESTAMP('2022-05-08T19:09:17Z', 'yyyy-MM-dd"T"HH:mm:ssXXX')) - TO_DATE('01/01/1970', 'MM/DD/YYYY')) * 24 * 60 * 60 from dual;
You should use:
TO_TIMESTAMP_TZ instead of TO_TIMESTAMP
the format model YYYY-MM-DD"T"HH24:MI:SS.FF TZD rather than incorrectly using MM twice, HH24 instead of HH, .FF instead of XXX, and TZD instead of hardcoding "Z".
Make sure you always convert your timestamp to UTC time zone (yours is already but others may not be)
Don't TRUNCate the timestamp to a DATE at midnight or you will lose the time component.
Like this:
SELECT ROUND(
(
TRUNC(timestamp_value AT TIME ZONE 'UTC', 'MI')
- DATE '1970-01-01'
) * 86400
+ EXTRACT(SECOND FROM timestamp_value AT TIME ZONE 'UTC')
) AS epoch_time
FROM (
SELECT TO_TIMESTAMP_TZ(
'2022-05-08T19:09:17Z',
'YYYY-MM-DD"T"HH24:MI:SS.FF TZD'
) AS timestamp_value
FROM DUAL
);
Which outputs:
EPOCH_TIME
1652033357
db<>fiddle here
Something like this:
TEST DATA
create table sample_inputs (ts_string) as
select '2022-05-08T16:49:34Z' from dual union all
select '2022-04-15T04:20:13.525Z' from dual
;
QUERY AND OUTPUT
with
prep (ts_string, ts) as (
select ts_string,
to_timestamp(ts_string, 'yyyy-mm-dd"T"hh24:mi:ss.ff"Z"')
from sample_inputs
)
select ts_string,
round((trunc(ts, 'mi') - date '1970-01-01') * 24 * 3600)
+ extract(second from ts)
as epoch
from prep;
TS_STRING EPOCH
-------------------------- -----------
2022-05-08T16:49:34Z 1652028574
2022-04-15T04:20:13.525Z 1649996413.525
NOTES
In your attempt there are several mistakes. The Oracle fractional-seconds element is ff, not xxx. You are missing the placeholder for the hard-coded Z at the end (you have "T" in your mask, which is correct, but you are missing the similar "Z"). HH is insufficient - it must be either HH24 or HH followed by AM (or equivalently PM) at the end. In your example, it is obviously HH24. And MM and mm mean the same thing in Oracle - this is not Unix. The element for minutes is mi or equivalently MI.
The query I wrote preserves fractional seconds in the epoch. Another question earlier today (perhaps yours too, under another user name) was closed as being a "duplicate" - but the claimed "duplicate" has absolutely nothing about preserving fractional seconds, when the input is an Oracle timestamp vs an Oracle date (which always does have a time component, but only in whole seconds).
I have to subtract 5 minutes from current timestamp and floor(truncate) it to nearest minute. Like '2016-02-23 06:10:39.0' should be '2016-02-23 06:05:00.0'.
I have found way to subtract 5 minutes as
systimestamp - interval '5' minute
EDIT 1:
I need timestamp in particular format,
TO_TIMESTAMP((systimestamp - interval '15' minute),'YYYY-MM-DD HH24:MI:SS.ff')
But this is giving
ORA-01830: date format picture ends before converting entire input string
But I am not able to floor it to nearest minute.
Please help. Thanks
You could use TRUNC() with the precision you want. To trunc only till minutes, use MI.
For example,
SQL> SELECT SYSTIMESTAMP, trunc(SYSTIMESTAMP - INTERVAL '5' MINUTE, 'MI') new_tmstmp
2 FROM dual;
SYSTIMESTAMP NEW_TMSTMP
----------------------------------- -------------------
16-MAR-16 04.44.02.379000 PM +05:30 03/16/2016 16:39:00
SQL>
Remember, the above output will be a DATE and not TIMESTAMP. You can explicitly CAST the date as timestamp:
SQL> SELECT SYSTIMESTAMP,CAST(trunc(SYSTIMESTAMP - INTERVAL '5' MINUTE,'MI') AS TIMESTAMP) tm
2 FROM dual;
SYSTIMESTAMP TM
----------------------------------- ------------------------------
16-MAR-16 04.53.25.802000 PM +05:30 2016-03-16 04:48:00.000000
SQL>
You can use trunc():
trunc(systimestamp - interval '5' minute, 'minute')
Given - number of minutes (number oracle type) from the beginning of a day, e.g. 480. Need to get standard oracle time, e.g. - 08:00:00 AM. Is there any good functions to do such operation?
Better use INTERVAL 'minutes' MINUTE to add the number of minutes. Easy to understand.
your_date_time + INTERVAL '480' MINUTE
For example,
SQL> SELECT TRUNC(SYSDATE), TRUNC(SYSDATE) + INTERVAL '480' MINUTE tmstamp FROM dual;
TRUNC(SYSDATE) TMSTAMP
------------------- -------------------
11/19/2015 00:00:00 11/19/2015 08:00:00
In fact, another way which is independent of NLS settings when you have to pass the date as literal. Thus, instead of using TO_DATE, use the ANSI Date literal which uses a fixed format 'YYYY-MM-DD' and is NLS independent.
SQL> SELECT DATE '2015-11-19' curr_date, DATE '2015-11-19' + INTERVAL '480' MINUTE tmstamp
2 FROM dual;
CURR_DATE TMSTAMP
------------------- -------------------
11/19/2015 00:00:00 11/19/2015 08:00:00
UDPATE
Given - number of minutes (number oracle type) from the beginning of a day, e.g. 480
If the minutes value is not static in SQL to be hard-coded, but a PL/SQL variable, then as #AlexPoole mentioned you need to use NUMTODSINTERVAL.
For example,
NUMTODSINTERVAL(480, 'MINUTE')
Having said that,
The Oracle PL/SQL NUMTODSINTERVAL function converts an input number to its specified Interval Day to Second Unit equivalent. The allowed interval units can be DAY, HOUR, MINUTE, or SECOND.
The return type of the function is INTERVAL.
For example,
SQL> SELECT NUMTODSINTERVAL(480, 'MINUTE') intrvl FROM DUAL;
INTRVL
---------------------------------------------------------------------
+000000000 08:00:00.000000000
Just add minutes/1440 to the date, e.g.
select to_date('1.1.2015','dd.mm.yyyy')+480/1440 from dual;
I am trying to subtract some days from 'current_timestamp' and converting that to timestamp using to_timestamp() function in Oracle. But I am always getting start of day time, that is 12 AM.
When I execute
select to_timestamp(current_timestamp - 3) from dual;
It will give me result like,
18-FEB-14 12.00.00.000000000 AM
But I need exact deduction of 3 days from current time.
Thanks!!!!
select current_timestamp - 3 ts from dual;
or
SELECT SYSTIMESTAMP - INTERVAL '3' DAY AS day FROM dual;
Will give you time as well:
select sysdate - 3 from dual;
Edit based on your comment:
select to_timestamp(to_char(sysdate-3,'DD-Mon-RR HH24:MI:SS'),'DD-Mon-RR HH24:MI:SS') from dual;
Or more simply:
select systimestamp - 3 from dual
An important difference is that SYSDATE gives you server time, and CURRENT_TIMESTAMP gives you session time.
Also, according to the documentation, TO_TIMESTAMP operates on CHAR, VARCHAR2, NCHAR, or NVARCHAR2 data types, not DATE. So I think you need to look elsewhere:
SELECT CAST (SYSDATE AS TIMESTAMP) from dual;
I know that to convert a Unix timestamp in milliseconds to an SQL timestamp I can use
SELECT TO_DATE('1970-01-01','YYYY-MM-DD HH24:MI:SS') +
(:timestamp / (1000*60*60*24)) FROM DUAL;
But I need a Timestamp, so I tried with
SELECT TO_TIMESTAMP('1970-01-01 00:00:00','YYYY-MM-DD HH24:MI:SSFF3') +
(:timestamp) from DUAL
Which gives me the error:
Error: ORA-01841: (full) year must be between -4713 and +9999, and not be 0
It seems that adding 1 to the timestamp always converts it to a day.
How can I do the same to get a real timestamp?
You will get a timestamp if you add an interval to a timestamp (see date/interval arithmetics).
As Benoit noticed, you can't specify an interval with seconds when there are more than about 2.1e9 of them:
SQL> SELECT numtodsinterval(2.2e9, 'SECOND'),
2 numtodsinterval(2.3e9, 'SECOND')
3 FROM dual;
NUMTODSINTERVAL(2.2E9,'SECOND' NUMTODSINTERVAL(2.3E9,'SECOND'
------------------------------- -------------------------------
+000024855 03:14:07.147483647 +000024855 03:14:07.147483647
This is why you should use minutes which do not lose precision. For example, assuming :TS is the unix timestamp (i.e. a number):
SQL> variable ts number;
SQL> -- determining unix timestamp with nanosecond precision
SQL> BEGIN
2 :ts := (to_date('2099-01-01 01:02:03', 'yyyy-mm-dd hh24:mi:ss')
3 - date '1970-01-01') * 1000*60*60*24
4 + 123.456789;
5 END;
6 /
ts
---------
4070912523123,456789
SQL> select timestamp '1970-01-01 00:00:00'
2 + numtodsinterval((:ts)/1000/60, 'MINUTE')
3 from dual;
TIMESTAMP'1970-01-0100:00:00'+NUMTODSINTERVAL((:TS)/1000/60,'MINUTE')
---------------------------------------------------------------------------
2099-01-01 01:02:03.123456789
There are two types:
Timestamps
Intervals
Intervals is what you get when you subtract timestamps, and it is nonsensical to add timestamps together.
If you need to get a millisecond interval, I would suggest to use a second interval and divide it by 1000:
I could suggest:
SELECT timestamp'1970-01-01 00:00:00' + (interval '1888' second(9) / 1000)
FROM dual
The problem here is that you cannot use more than 9 digits in a same timestamp literal.
If you need to ad 2,061,464,797,255 milliseconds to the epoch I can suggest:
SELECT TIMESTAMP'1970-01-01 00:00:00'
+ INTERVAL '2' SECOND(9) * 1000000000
+ INTERVAL '061464797' SECOND(9)
+ INTERVAL '255' SECOND(3) / 1000
FROM dual
You get 2035-04-29 13:06:37.255000000
It seems to be subject to the 2038 bug: TIMESTAMP'1970-01-01 00:00:00' + 3 billion seconds does not work, whereas it works with 2 billion.
I've posted here some methods to convert nanoseconds to timestamp and timestamp to nanoseconds. These methods are not affected by time zones and have a nanosecond precision.
You just need to adjust it to use milliseconds instead of nanoseconds.
SELECT TIMESTAMP '1970-01-01 00:00:00 UTC' + numtodsinterval(
1598434427263 --Replace line with desired milliseconds
/ 1000, 'SECOND') AS TIMESTAMP FROM dual;
TIMESTAMP
26/08/20 09:33:47,263000000 UTC
Use
SELECT TIMESTAMP '1970-01-01 00:00:00.1234' + INTERVAL '1 00:00:00' DAY TO SECOND
AS ts
FROM dual;