Date conversion - Oracle sql [duplicate] - sql

I need to convert a date from a TextBox from date to epoch time so that I can insert it into Oracle DB.
I managed to convert from epoch to date as below, but couldn't find a way to convert it the other way.
SelectCommand="SELECT ID,
COMPANY,
FIRST_NAME,
LAST_NAME,
ID_NUMBER,
(SELECT TO_CHAR(TO_DATE('01-JAN-1970','DD/MM/YYYY')
+(TRAINING_DATE/60/60/24), 'MM/DD/YYYY') FROM dual) AS TRAINING_DATE,
(SELECT TO_CHAR(TO_DATE('01-JAN-1970','DD/MM/YYYY')
+(TRAINING_VALABILITY/60/60/24),'MM/DD/YYYY') FROM dual) AS TRAINING_VALABILITY
FROM CONTRACTORS
ORDER BY COMPANY"

Subtracting DATE '1970-01-01' from the value will give the number of days (and fractional hours/minutes/seconds) difference and then you can multiply by 24*60*60:
(date_value - DATE '1970-01-01')*24*60*60
Update:
Typically, epoch time is measured from 1970-01-01T00:00:00 UTC. If your date is not in UTC then you will need to convert time zones.
For example, if your date has the time zone Europe/Berlin:
( CAST(
FROM_TZ(
CAST( date_value AS TIMESTAMP ), -- Cast to timestamp
'Europe/Berlin' -- Convert to expected Time Zone
)
AT TIME ZONE 'UTC' -- Convert Time Zone to UTC
AS DATE -- Cast back to DATE data type
)
- DATE '1970-01-01'
)*24*60*60
db<>fiddle

UpdateCommand="UPDATE CONTRACTORS
SET COMPANY=:COMPANY,
FIRST_NAME=:FIRST_NAME,
LAST_NAME=:LAST_NAME,
ID_NUMBER=:ID_NUMBER,
TRAINING_DATE=(TO_DATE(:TRAINING_DATE, 'MM-DD-YYYY HH24:MI:SS') - TO_DATE('01-JAN-1970','DD/MM/YYYY'))*24*60*60,
TRAINING_VALABILITY=(TO_DATE(:TRAINING_VALABILITY, 'MM-DD-YY`enter code here`YY HH24:MI:SS') - TO_DATE('01-JAN-1970','DD/MM/YYYY'))*24*60*60
WHERE (ID=:ID)"

I use this solution which works correctly whether the input date, in local time, is during Daylight Saving Time (DST) or not.
SELECT Round((Cast(Sys_extract_utc( Cast( your_date_field AS TIMESTAMP )) AS DATE) - To_date('1970-01-01','YYYY-MM-DD HH24MISS')) *24*60*60) AS epoch FROM dual;
-- 'your_date_field'
-- '20210112' -> 1610427600 (no DST)
-- '20210512' -> 1620792000 (DST)

Related

Oracle: Error in converting DateTime to Epoch

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).

How to substract 2 varchar dates in oracle?

I have these varchar : 20211026231735.
So I would like a query to substract actual sysdate to that date and convert the substraction to DAY HOURS AND SECONDS.
select TO_CHAR(SYSDATE,'YYYYMMDDHH24MISS') - start_time from TABLEA where job_name='jOB_AA_BB';
I get 4220.
Any help please? Thanks
When you do datetime arithmetic with the DATE datatype, you get back a NUMBER of days. To get an INTERVAL you can subtract two TIMESTAMPs. You don't say what the data type is for start_time, but you might get away with this:
select localtimestamp - start_time
from tablea where job_name='jOB_AA_BB';
LOCALTIMESTAMP gives you a TIMESTAMP value in the current session time zone. There's also CURRENT_TIMESTAMP, which give you the same thing in a TIMESTAMP WITH TIME ZONE and SYSTIMESTAMP that gives you the database time in TIMESTAMP WITH TIME ZONE. You may need to convert your start_time to avoid time zone differences, if any.
You can us the function numtodsinterval to convert the results of date arithmetic to an interval. If necessary then use extract to pull out the needed components.
with tablea(job_name, start_time) as
(select 'jOB_AA_BB','20211026231735' from dual)
select numtodsinterval((SYSDATE - to_date( start_time,'yyyymmddhh24miss')),'hour') date_diff
from tablea where job_name='jOB_AA_BB' ;
with tablea(job_name, start_time) as
(select 'jOB_AA_BB','20211026231735' from dual)
select extract (hour from date_diff) || ':' || extract (minute from date_diff)
from (
select numtodsinterval((sysdate - to_date( start_time,'yyyymmddhh24miss')),'day') date_diff
from tablea where job_name='jOB_AA_BB'
);
NOTE: I am not sure how you got any result, other than an error, as your query winds up as a string - a string. You should not convert sysdate to a string but your string to a date (better yet store it as the proper data type - date).
You can convert the value to a date (rather than converting SYSDATE to a string) and then subtract and explicitly return the value as an INTERVAL DAY TO SECOND type:
SELECT (SYSDATE - TO_DATE('20211026231735', 'YYYYMMDDHH24MISS')) DAY TO SECOND
FROM DUAL;
Or, for your table:
SELECT (SYSDATE - TO_DATE(start_time,'YYYYMMDDHH24MISS')) DAY(5) TO SECOND
FROM TABLEA
WHERE job_name='jOB_AA_BB';
db<>fiddle here

Casting Local Time to UTC Formating Incorrect

HIRE_DATE is in a 'DATE' column. The timestamp is local (Los Angeles); I would like to convert it to UTC.
I can't for the life of me fathom why the UTC output is mangled (Last 2 digits of YY is the DD; and vice-versa) -- and the time does not convert to UTC.
HIRE_DATE: 30/04/2019 12:00:00 AM
select from_tz(to_timestamp(HIRE_DATE,'DD-MM-YY HH24:MI:SS'), 'America/Los_Angeles') at time zone 'UTC' from TABLE
OUTPUT: 19/04/2030 12:00:00 AM
If HIRE_DATE is a DATE data type then you don't need TO_TIMESTAMP.
TO_TIMESTAMP is used to convert a string (i.e. VARCHAR2) into a TIMESTAMP value but you have a DATE value.
Just do
select from_tz(CAST(HIRE_DATE AS TIMESTAMP), 'America/Los_Angeles') at time zone 'UTC'
from TABLE
Actually I don't understand why FROM_TZ does not accept DATE values whereas almost any other date/timestamp related function accept either DATE or TIMESTAMP value as input.
Note, the default output display format of this query is defined by current user session NLS_TIMESTAMP_TZ_FORMAT setting. If you are not satisfied with the output format, either change NLS_TIMESTAMP_TZ_FORMAT setting by executing ALTER SESSION SET NLS_TIMESTAMP_TZ_FORMAT = '...' or use TO_CHAR function to set output format explicitly.
Instead of
... AT TIME ZONE 'UTC'
you can also use
SYS_EXTRACT_UTC(...)
The upper returns a TIMESTAMP WITH TIME ZONE value, the second one returns a TIMESTAMP value.
Would this do any good?
SQL> select from_tz(cast (sysdate as timestamp), 'UTC') result from dual;
RESULT
---------------------------------------------------------------------------
27.09.20 10:59:28,000000 UTC
Or, in your case
select from_tz(cast (hire_date as timestamp), 'UTC' from dual
No need to apply any format mask to hire_date as it is a DATE datatype (at least, that's what you said).
You use the word "convert" which can mean one of two things:
change the data type, which is what FROM_TZ does
change the value from one time zone to another, which FROM_TZ does not do.
You didn't give your expected output, so we may misunderstand.
To change the data type:
with data(dte) as (
select date '2019-04-30' + interval '12' hour from dual
)
select from_tz(cast(dte as timestamp), 'America/Los_Angeles') from data
FROM_TZ(CAST(DTEASTIMESTAMP),'AMERICA/LOS_ANGELES')
30-APR-19 12.00.00.000000 PM AMERICA/LOS_ANGELES
To get the simultaneous datetime value in UTC:
with data(dte) as (
select date '2019-04-30' + interval '12' hour from dual
)
select cast(sys_extract_utc(from_tz(cast(dte as timestamp), 'America/Los_Angeles')) as date) from data
CAST(SYS_EXTRACT_UTC(FROM_TZ(CAST(DTEASTIMESTAMP),'AMERICA/LOS_ANGELES'))ASDATE)
2019-04-30 19:00:00

Extract time from a column

I've a column like last_located_time which contain values like
2017-05-13T17:33:36.000+0000.
I have tried to remove only time, but no luck.
SELECT USERNAME, TO_DATE(SUBSTR(LAST_LOCATED_TIME,11,17),'HH:MI:SS') "lAST TIME"
FROM Tb_089
How should I extract only time value from the columns for all users?
Thanks in advance!
If you want the time component in the UTC time zone (so all times are being displayed in a common time zone) then:
(assuming you have a TIMESTAMP WITH TIME ZONE data type)
SELECT TO_CHAR(
last_located_time AT TIME ZONE 'UTC',
'HH24:MI:SS'
)
FROM Tb_089;
If you, instead, the column is an ISO 8601 formatted string:
SELECT TO_CHAR(
TO_TIMESTAMP_TZ(
last_located_time,
'YYYY-MM-DD"T"HH24:MI:SS.FFTZHTZM'
) AT TIME ZONE 'UTC',
'HH24:MI:SS'
)
FROM Tb_089;
If you want the time component as an interval:
SELECT CAST( utc_last_located_time AS TIMESTAMP ) - TRUNC( utc_last_located_time )
AS time_interval
FROM (
SELECT TO_TIMESTAMP_TZ(
last_located_time,
'YYYY-MM-DD"T"HH24:MI:SS.FFTZHTZM'
) AT TIME ZONE 'UTC' AS utc_last_located_time
FROM Tb_089
);
If you want the time component of the string (without adjusting for disparate time zones) then you could just do:
SELECT SUBSTR( last_located_time, 12, 8 )
FROM Tb_089
To_Date is used to convert Char and Varchar2 into Date.
You need to use To_Char which is opposite of To_Date
Select To_Char(LAST_LOCATED_TIME, 'HH24:MI:SS') "Last Time" from Tb_089;

Convert from date to epoch-Oracle

I need to convert a date from a TextBox from date to epoch time so that I can insert it into Oracle DB.
I managed to convert from epoch to date as below, but couldn't find a way to convert it the other way.
SelectCommand="SELECT ID,
COMPANY,
FIRST_NAME,
LAST_NAME,
ID_NUMBER,
(SELECT TO_CHAR(TO_DATE('01-JAN-1970','DD/MM/YYYY')
+(TRAINING_DATE/60/60/24), 'MM/DD/YYYY') FROM dual) AS TRAINING_DATE,
(SELECT TO_CHAR(TO_DATE('01-JAN-1970','DD/MM/YYYY')
+(TRAINING_VALABILITY/60/60/24),'MM/DD/YYYY') FROM dual) AS TRAINING_VALABILITY
FROM CONTRACTORS
ORDER BY COMPANY"
Subtracting DATE '1970-01-01' from the value will give the number of days (and fractional hours/minutes/seconds) difference and then you can multiply by 24*60*60:
(date_value - DATE '1970-01-01')*24*60*60
Update:
Typically, epoch time is measured from 1970-01-01T00:00:00 UTC. If your date is not in UTC then you will need to convert time zones.
For example, if your date has the time zone Europe/Berlin:
( CAST(
FROM_TZ(
CAST( date_value AS TIMESTAMP ), -- Cast to timestamp
'Europe/Berlin' -- Convert to expected Time Zone
)
AT TIME ZONE 'UTC' -- Convert Time Zone to UTC
AS DATE -- Cast back to DATE data type
)
- DATE '1970-01-01'
)*24*60*60
db<>fiddle
UpdateCommand="UPDATE CONTRACTORS
SET COMPANY=:COMPANY,
FIRST_NAME=:FIRST_NAME,
LAST_NAME=:LAST_NAME,
ID_NUMBER=:ID_NUMBER,
TRAINING_DATE=(TO_DATE(:TRAINING_DATE, 'MM-DD-YYYY HH24:MI:SS') - TO_DATE('01-JAN-1970','DD/MM/YYYY'))*24*60*60,
TRAINING_VALABILITY=(TO_DATE(:TRAINING_VALABILITY, 'MM-DD-YY`enter code here`YY HH24:MI:SS') - TO_DATE('01-JAN-1970','DD/MM/YYYY'))*24*60*60
WHERE (ID=:ID)"
I use this solution which works correctly whether the input date, in local time, is during Daylight Saving Time (DST) or not.
SELECT Round((Cast(Sys_extract_utc( Cast( your_date_field AS TIMESTAMP )) AS DATE) - To_date('1970-01-01','YYYY-MM-DD HH24MISS')) *24*60*60) AS epoch FROM dual;
-- 'your_date_field'
-- '20210112' -> 1610427600 (no DST)
-- '20210512' -> 1620792000 (DST)