Get Exact timestamp value? - sql

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;

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

Filtering a dataset by date and time Oracle SQL through Power BI

I'm having trouble with filtering a date and time for anything two hours before and sooner. I tried this:
SELECT *
FROM
table
where
date >= sysdate - 1
AND
TO_DATE( Time, 'HH24:MI:SS' ) >= TO_DATE( sysdate, 'HH24:MI:SS' ) - 2
But I'm getting an inconsistent type error which is what I thought I was handling with the TO_DATE() function but I guess not.
sysdate is already a date (and time), so TO_DATE( sysdate, 'HH24:MI:SS' ) doesn't make any sense.
You didn't provide your data types for your date and time columns in table, so I'm going to assume they're both varchar2(10) with formats MM/DD/YYYY and HH24:MI:SS respectively.
I'm also going to go ahead and change your example table and column names, since they're invalid names to use in a real query.
-- example data
with my_table as (select '06/13/2019' as date_column, '09:40:34' as time_column from dual)
-- your query
SELECT *
FROM
my_table
where
to_date(date_column || ' ' || time_column, 'MM/DD/YYYY HH24:MI:SS') >= sysdate - 2/24
What I'm doing here is to combine your date and time strings into one date-time string, then converting it to an Oracle date type (actually date+time). Then we compare it to sysdate - 2/24, which says to take the current time and subtract 2/24ths of a day, which is 2 hours.
For this example, you might need to change the example data date_column and time_column values to something from the past 2 hours, depending on when you run this and what time zone you're in.

Select data between timestamps

Usecase: Query to select the records for a whole day and it should run regularly.
This is my query.
Select to_char(in_date + interval '12' hour, 'DD-MON-YYYY HH24:MI:SS')
from my_table
where incoming_date > sysdate-2 and incoming_date < sysdate
I need to select yesterday's data only. Because of the conversion in the select statement I got today's data also. How do I select only yesterday's data? My DB is in UTC+7.00 standard. I need to display it in local standard so that I did a conversion in select statement. And how do I display only yesterday's data?
I'm stuck. Please help me
To get all data from yesterday you should use
SELECT TO_CHAR(IN_DATE + INTERVAL '12' HOUR, 'DD-MON-YYYY HH24:MI:SS')
FROM MY_TABLE
WHERE INCOMING_DATE BETWEEN TRUNC(SYSDATE) - INTERVAL '1' DAY
AND TRUNC(SYSDATE) - INTERVAL '1' SECOND
If, for example, SYSDATE is 05-NOV-2017 18:56:35, the time interval used in the BETWEEN comparison will be from 04-NOV-2017 00:00:00 to 04-NOV-2017 23:59:59. BETWEEN comparisons are inclusive of both endpoints so this will only return data with an INCOMING_DATE of sometime on 04-NOV-2017, in this example.
Best of luck.
only to get the
yesterday's data
make your
WHERE condition as
incoming_date between trunc(sysdate) - interval '1' day and trunc(sysdate) - interval '1' second
My DB is in UTC+7.00 standard. I need to display it in local standard so that I did a conversion in select statement.
Using a magic value (INTERVAL '12' HOUR) does not describe what it means or the assumptions you made when chosing that value. Instead you can better describe the process by using FROM_TS( timestampvalue, timezonestring ) to convert the value from a TIMESTAMP to a TIMESTAMP WITH TIME ZONE data type and then use AT LOCAL TIME to convert it to the local time. Then if you have daylight savings time or port the query to another international location then it will still display in the current local time. Like this:
SELECT TO_CHAR(
FROM_TZ( CAST( in_date AS TIMESTAMP ), '+07:00' ) AT LOCAL TIME,
'DD-MON-YYYY HH24:MI:SS'
)
FROM my_table
WHERE incoming_date >= TRUNC( SYSDATE ) - INTERVAL '1' DAY
AND incoming_date < TRUNC( SYSDATE )
And how do I display only yesterday's data?
TRUNC( SYSDATE ) will truncate today's date back to midnight. To get yesterday's data then you can get values that are greater or equal to TRUNC( SYSDATE ) - INTERVAL '1' DAY (one day before midnight today) and also less than TRUNC( SYSDATE ) (midnight today).
I'm not exactly sure I get your question, but I think I can explain some stuff.
I'll be assuming your table is a bit like this:
date_added | some_data | some_more_data
------------|-----------|----------------
date | data1 | data2
As I understand your goal is to fetch all the rows that were added to a table the day before the query is run using a select statement. but your current attempt fails at doing so by also returning today's results.
Here is what's happening (I think):
SYSDATE doesn't just give you the current date, it also gives you the time. You can see that for your self by simply altering your current session and setting the date/time format to one that includes both time and date
ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MON-YYYY HH24:MI:SS';
The reason why you would be getting today's rows is simple, your query is asking for all the rows who's date_added field is between right now and right now - 24 hours. Not today and today - 24 hours.
So what is the solution?
Use the TRUNC function to trim the SYSDATE to the day instead!
https://docs.oracle.com/cd/B19306_01/server.102/b14200/functions201.htm
SELECT
T.*
FROM
MY_TABLE T
WHERE
T.DATE_ADDED BETWEEN (TRUNC(SYSDATE,'day') - 1) AND TRUNC(SYSDATE,'day');
As you did mention timezones being a thing keep in mind that SYSDATE returns the date on the server itself and not your computer's.
More on that here: https://stackoverflow.com/a/17925834/7655979
Usually I compare the date only using Trunc.
WHERE trunc(incoming_date) = trunc(sysdate-1)

Using "Interval" in Oracle where "Interval" is a value from a table

I need to generate a list of values in an Oracle DB with the following columns of data:
ITEM_TYPE VARCHAR2(20)
ITEM_LAST_UPDATED DATE
ITEM_UPDATE_TOLERANCE NUMBER(1)
The only data that should be send out to the console would be items that have the date in 'ITEM_LAST_UPDATED' less than the sysdate minus the integer value within 'ITEM_UPDATE_TOLERANCE'.
So, if I wanted to just show the ones that were one hour past due, I can do:
select ITEM_TYPE from MY_TABLE
where
to_char(ITEM_LAST_UPDATED, 'DD-MON-YYYY HH24:MI')
<=
to_char(sysdate - interval '1' hour, 'DD-MON-YYYY HH24:MI');
However, rather than using the '1' in the above statement, I need to replace it with the numeric value of ITEM_UPDATE_TOLERANCE.
I tried several different versions, but all error (such as):
select ITEM_TYPE from MY_TABLE
where
to_char(ITEM_LAST_UPDATED, 'DD-MON-YYYY HH24:MI')
<=
to_char(sysdate - interval to_number(ITEM_UPDATE_TOLERANCE) hour, 'DD-MON-YYYY HH24:MI');
Why are you converting a perfect DATE column to a character value just to compare it another DATE value converted to a character column.
Simply use:
ITEM_LAST_UPDATED <= sysdate - interval '1' hour
To achieve what you want, just multiply the value:
ITEM_LAST_UPDATED <= sysdate - (interval '1' hour) * ITEM_UPDATE_TOLERANCE
There is also absolutely no need to convert a number to a number using the to_number() function.
As an alternative to #a_horse_with_no_name's interval multiplication trick, or San's division method, you can also use the numtodsinterval() function:
ITEM_LAST_UPDATED <= sysdate - numtodsinterval(ITEM_UPDATE_TOLERANCE, 'HOUR')
As an example:
select sysdate, sysdate - numtodsinterval(3, 'HOUR') from dual;
SYSDATE SYSDATE-NUMTODSINTE
------------------- -------------------
2014-03-07 19:08:27 2014-03-07 16:08:27
Well you can try using simple calculation
select ITEM_TYPE from MY_TABLE
where
ITEM_LAST_UPDATED
<=
sysdate - (ITEM_UPDATE_TOLERANCE/24);
Calculation of ITEM_UPDATE_TOLERANCE/24 will convert hours into days and then can be subtracted from sysdate.

How to trunc a date to seconds in Oracle

This page mentions how to trunc a timestamp to minutes/hours/etc. in Oracle.
How would you trunc a timestamp to seconds in the same manner?
Since the precision of DATE is to the second (and no fractions of seconds), there is no need to TRUNC at all.
The data type TIMESTAMP allows for fractions of seconds. If you convert it to a DATE the fractional seconds will be removed - e.g.
select cast(systimestamp as date)
from dual;
I am sorry, but all my predecessors seem to be wrong.
select cast(systimestamp as date) from dual
..does not truncate, but rounds to the next second instead.
I use a function:
CREATE OR REPLACE FUNCTION TRUNC_TS(TS IN TIMESTAMP) RETURN DATE AS
BEGIN
RETURN TS;
END;
For example:
SELECT systimestamp
,trunc_ts(systimestamp) date_trunc
,CAST(systimestamp AS DATE) date_cast
FROM dual;
Returns:
SYSTIMESTAMP DATE_TRUNC DATE_CAST
21.01.10 15:03:34,567350 +01:00 21.01.2010 15:03:34 21.01.2010 15:03:35
On the general topic of truncating Oracle dates, here's the documentation link for the format models that can be used in date trunc() AND round() functions
http://download.oracle.com/docs/cd/B28359_01/server.111/b28286/functions242.htm#sthref2718
"Seconds" is not listed because the granularity of the DATE datatype is seconds.
I used function like this:
FUNCTION trunc_sec(p_ts IN timestamp)
IS
p_res timestamp;
BEGIN
RETURN TO_TIMESTAMP(TO_CHAR(p_ts, 'YYYYMMDDHH24MI'), 'YYYYMMDDHH24MI');
END trunc_sec;
trunc work to min only, cast to date to_char(START_TIME,'YYYYMMDDHH24MISS')
or simply select to_char(current_timestamp, 'YYYYMMDDHH24MISS') from dual;
https://www.techonthenet.com/oracle/functions/trunc_date.php
To truncate a timestamp to seconds you can cast it to a date:
CAST(timestamp AS DATE)
To then perform the TRUNC's in the article:
TRUNC(CAST(timestamp AS DATE), 'YEAR')
Something on the order of:
select to_char(current_timestamp, 'SS') from dual;