Convert from date to epoch-Oracle - 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

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

Date conversion - Oracle sql [duplicate]

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)

to_Char(DATE) with time

I have a DB (Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production). In there is a table (Course) in which I have a Date column (start_dte). I want to format the output to a char so I used:
SELECT start_dte,
to_Char(start_dte) AS start_dte_2,
to_Char(start_dte,'DD.MM.YYYY') AS start_dte_3,
to_Char(start_dte,'DD.MM.YYYY HH24:MI:SS') AS start_dte_4,
to_Char(start_dte,'DD.MM.YYYY HH12:MI:SS') AS start_dte_5,
to_Char(start_dte,'DD.MM.YYYY HH.MI.SSXFF AM') AS start_dte_6,
to_Char(start_dte,'DD.MM.YYYY HH24:MI:SSxFF') AS start_dte_7,
to_Char(start_dte,'DD-MON-YYYY HH24:MI:SSxFF TZH:TZM') AS start_dte_8
FROM Course
The Results:
Number 6,7,8 give me
java.sql.SQLException: ORA-01821: date format not recognized
6 has the same format as:
SELECT value
FROM V$NLS_PARAMETERS
WHERE parameter = 'NLS_TIME_FORMAT'
7 and 8 are taken from the Oracle documentation but this is only for timestamps. So what i am missing? I know the actual datatype should be datetime but I only have read access to that DB. What i would actually like:
Or even better:
A DATE doesn't have any time zone information, so if you want to adjust the displayed time then you'll need to specify which time zone that date nominally represents, and which time zone you want to convert it to.
An an example, if your stored date represents UTC and you want to see the equivalent local time in Paris, you can state that the stored time is UTC by casting it as a plain timestamp and passing that into the from_tz() function; and then specify the target timezone with at:
-- CTE for your sample data
with course (start_dte) as (
select cast(timestamp '2018-10-17 14:00:00' as date) from dual
)
-- actual query
select from_tz(cast(start_dte as timestamp), 'UTC')
at time zone 'Europe/Paris' as start_timestamp_tz
from course;
START_TIMESTAMP_TZ
------------------------------------------
2018-10-17 16:00:00.000000000 EUROPE/PARIS
Since you're querying this via JDBC you probably want to retrieve that as its native data type, and then choose how to display it locally. (But you could presumably query it as a date and adjust it in Java too...)
If you want to convert it to a string on the DB side, though, just use the format model you already used:
select to_char(from_tz(cast(start_dte as timestamp), 'UTC')
at time zone 'Europe/Paris', 'DD.MM.YYYY HH24:MI') as start_date
from course;
START_DATE
----------------
17.10.2018 16:00
Getting it into two fields is also simple, and if you don't want to repeat the conversion you can use a CTE or an inline view:
select to_char(start_timestamp_tz, 'DD.MM.YYYY') as start_date,
to_char(start_timestamp_tz, 'HH24:MI') as start_time
from (
select from_tz(cast(start_dte as timestamp), 'UTC')
at time zone 'Europe/Paris' as start_timestamp_tz
from course
);
START_DATE START_TIME
---------- ----------
17.10.2018 16:00
But it sounds like Java should be doing that conversion to strings for display.
What i would actually like:
| START_DATE |
|------------------|
| 17.10.2018 16:00 |
Or even better:
| START_DATE | START_TIME |
|------------|------------|
| 17.10.2018 | 16:00 |
Use:
SELECT to_Char(start_dte,'DD.MM.YYYY') AS start_date,
to_Char(start_dte,'HH24:MI') AS start_time
FROM Course
If your data is stored in the table in one time zone (i.e. UTC) and you want it in another time zone then use:
CAST( date_value AS TIMESTAMP ) to convert it from a DATE data type to a TIMESTAMP data type.
FROM_TZ( timestamp_value, timezone_string ) to convert it from a TIMESTAMP data type to a TIMESTAMP WITH TIME ZONE data type at the given time zone.
timestamp_with_timezone_value AT TIME ZONE timezone_string to convert it from one time zone to another time zone.
Like this:
SELECT TO_CHAR(
FROM_TZ( CAST( start_dte AS TIMESTAMP ), 'UTC' ) AT TIME ZONE 'Europe/Berlin',
'DD.MM.YYYY'
) AS start_date,
TO_CHAR(
FROM_TZ( CAST( start_dte AS TIMESTAMP ), 'UTC' ) AT TIME ZONE 'Europe/Berlin',
'HH24:MI'
) AS start_time
FROM Course
start_dte is a DATE value.
DATE does neither have fractional seconds (i.e. XFF) nor time zone information (i.e. TZH:TZM)
Use TIMESTAMP WITH TIME ZONE is you like to get such output.

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;