Oracle query on time (and not date) - sql

How can you query on just the time portion of an Orace date field. Ie:
select * from mytable
where
date_column < '05:30:00'
Want the query to return any rows where the time represented by date_column is less than 5:30 regardless of the date.

You can try like this:
select * from mytable
where
to_char( date_column, 'HH24:MI:SS' ) < '05:30:00'

You can see how far the date is from midnight, and filter on that:
select * from mytable
where date_column - trunc(date_column) < 5.5/24
The date_column - trunc(date_column) calculation will give you a fraction of a day, as is normal for date arithmetic. The 5.5/24 is the fraction of the day represented by the time at 05:30; 5.5 hours out of 24 hours.
If the column was a timestamp instead of a date you'd see an interval data type as the result of the subtraction. You can use an interval literal anyway if you prefer or find it easier to understand than 5.5/24 (or have more complicated times to compare, which are harder to express as a fraction):
select * from mytable
where date_column < trunc(date_column) + interval '0 05:30:00' day to second;
This way round you're comparing the date in your column with the truncated date (i.e. midnight on that day) with 5 hours 30 minutes added to it, which is 05:30 the same day.
Quick demo with simple data in a CTE, and a third very slight variant, but they all get the same result:
with mytable (date_column) as (
select to_date('2016-04-15 05:29:29', 'YYYY-MM-DD HH24:MI:SS') from dual
union all select to_date('2016-04-14 05:29:29', 'YYYY-MM-DD HH24:MI:SS') from dual
union all select to_date('2016-04-15 05:30:30', 'YYYY-MM-DD HH24:MI:SS') from dual
)
select * from mytable
where date_column < trunc(date_column) + 5.5/24;
DATE_COLUMN
-------------------
2016-04-15 05:29:29
2016-04-14 05:29:29
Note though that any manipulation of the column like this will prevent an index being used. If you have to do this regularly it might be worth adding a virtual column/index which does that calculation.

You need to cast the time back to date, otherwise you're simply doing string comparison.
Oracle doesn't really have a clever way of doing this. Simplest to cast both dates to the same day and do the comparison.
I.e.
select *
from mytable
where to_date ('01.01.2000 ' || to_char (date_column, 'hh24:mi:ss'), 'dd.mm.yyyy hh24:mi:ss') <
to_date ('01.01.2000' || '05:30:00', 'dd.mm.yyyy hh24:mi:ss')

Related

Oracle query time on date fields

I have a column of type DATE stored data are contains date and time . I can see value when i do
select CAST(MSG_DT AS TIMESTAMP) from table;
this is the output
17-MAR-08 15:38:59,000000000
I have to select the row using
Only date
select CAST(MSG_DT AS TIMESTAMP) from
MWRB_RECEIVE where
MSG_DT >= TO_DATE( '2000-02-03' ,'YYYY-MM-DD')
and
MSG_DT <= TO_DATE( '2010-02-03' ,'YYYY-MM-DD')
Only time (eg: every message between 12:00:11 and 23:02:55)
In DB2 i can do
SELECT *
FROM TABLE
WHERE DATE(INS_TMS) = '2014-02-18'
SELECT *
FROM TABLE
WHERE TIME(INS_TMS) > '09.55.00'
In ORACLE I can't see the equivalent.
Try this:
SELECT *
FROM your_table
WHERE TO_CHAR (start_date, 'yyyy-mm-dd') = '2014-10-06'
AND TO_CHAR (start_date, 'hh24:mi:ss') > '10:00:00'
Why are you casting the column value to a TIMESTAMP when the column in the database is a DATE type? The fractional part of the seconds will always be 0, as DATE only has resolution to the seconds value. You need to add the hours,minutes, and seconds format specifier to the query:
select MSG_DT from
MWRB_RECEIVE
where MSG_DT between TO_DATE( '2000-02-03 12:00:11' ,'YYYY-MM-DD HH24:MI:SS') AND
TO_DATE( '2010-02-03 23:02:55' ,'YYYY-MM-DD HH24:MI:SS')
There is no need to split date and hour, you can have it in a single where clause
where field > to_date('20121212 12:12:12, 'YYYYMMDD HH24:MI:SS')
Check for your reference oracle to_date() as it seems the only thing you need

Reason for using trunc function on dates in Oracle

I am currently working in a project on a Oracle database. I have observed in the application code that dates are almost never used directly. Instead, they are always used in conjunction with the trunc function (TRUNC(SYSDATE), TRUNC(event_date), etc.)
Can anyone explain the reason behind using the trunc function instead of using the date directly?
A DATE in Oracle has not only a date part, but also a time part. This can lead to surprising results when querying data, e.g. the query
with v_data(pk, dt) as (
select 1, to_date('2014-06-25 09:00:00', 'YYYY-MM-DD hh24:mi:ss') from dual union all
select 2, to_date('2014-06-26 09:00:00', 'YYYY-MM-DD hh24:mi:ss') from dual union all
select 3, to_date('2014-06-27 09:00:00', 'YYYY-MM-DD hh24:mi:ss') from dual)
select * from v_data where dt = date '2014-06-25'
will return no rows, since you're comparing to 2014-06-25 at midnight.
The usual workaround for this is to use TRUNC() to get rid of the time part:
with v_data(pk, dt) as (
select 1, to_date('2014-06-25 09:00:00', 'YYYY-MM-DD hh24:mi:ss') from dual union all
select 2, to_date('2014-06-26 09:00:00', 'YYYY-MM-DD hh24:mi:ss') from dual union all
select 3, to_date('2014-06-27 09:00:00', 'YYYY-MM-DD hh24:mi:ss') from dual)
select * from v_data where trunc(dt) = date '2014-06-25'
Other, somewhat less frequently used approaches for this problem include:
convert both dates with to_char('YYYY-MM-DD') and check for equality
use a between clause: WHERE dt between date '2014-06-25' and date '2014-06-26'
You use the trunc() function to remove the time component of the date. By default, the date data type in Oracle stores both dates and times.
The trunc() function also takes a format argument, so you can remove other components of the dates, not just the time. For instance, you can trunc to the nearest hour. However, without the format, the purpose is to remove the time component.
If you the column in your table, for example event_date, is indexed, then avoid using trunc on the column because if you do that then Oracle can't use the index (otherwise, you can create a function based index)
so do not do:
select *
from mytable
where trunc(event_date) < date '2014-01-01'
but instead do
select *
from mytable
where event_date < date '2014-01-02'
In the second case, Oracle can do a range scan on the index on event_date, in the first case it has to do a full table scan.

Select Dates where time is less or equal to '12:00' Oracle

I require a query that selects rows where the time is less or equal to 12:00
I had something like this in mind:
SELECT daterow FROM datecolumn WHERE daterow <= TO_DATE('12:00, HH24:MI')
However i get an error:
ORA-01843: not a valid month
How would i go about to get all rows that have a time less than 12:00 mid-day?
Try this,
SELECT daterow FROM datecolumn WHERE daterow <= TO_DATE('12:00', 'HH24:MI');
Try This:
SELECT daterow FROM datecolumn
WHERE TO_DATE(daterow,'HH24:MI') <= TO_DATE('12:00', 'HH24:MI');
In order to select all rows where time portion of the daterow column value is less than or equal to mid-day 12:00 you can use to_char() function to extract hour and minutes and to_number() to convert it to a number for further comparison:
-- sample of data. Just for the sake of demonstration
SQL> with t1(col) as(
2 select sysdate - to_dsinterval('P0DT3H') from dual union all
3 select sysdate - to_dsinterval('P0DT2H') from dual union all
4 select sysdate - to_dsinterval('P0DT1H') from dual union all
5 select sysdate + to_dsinterval('P0DT3H') from dual union all
6 select sysdate + to_dsinterval('-P2DT0H') from dual
7 )
8 select to_char(col, 'dd.mm.yyyy hh24:mi:ss') as res
9 from t1 t
10 where to_number(to_char(col, 'hh24mi')) <= 1200
11 ;
Result:
RES
-------------------
26.08.2013 08:10:59
26.08.2013 09:10:59
26.08.2013 10:10:59
24.08.2013 11:10:59
Sorry, but <= TO_DATE('12:00', 'HH24:MI') does not work. It does not extract the hour and minute from each date and compares it to 12:00. Instead it constructs the date representing high noon on the fisrt of the current month and compares each date to this date.
If you want to extract something from a date, use the extract function.
Attention: When using extract on a date, and want to extract hours, minutes or seconds, you have first to convert the date to a timestamp.
Example:
SELECT
extract(hour FROM cast(A AS TIMESTAMP)) AS h,
extract(MINUTE FROM cast(A AS TIMESTAMP)) AS m
FROM
DEMO
;
You can find a complete example on sqlfiddle. The example also shows that the to_date method doesn't work.

How to subtract Sys with Timestamp from field and get hours and minutes

This is my current query
SELECT
TABLE1.OUT_NO,
To_char(sysdate, 'MM-DD-YYYY HH24:MI:SS') as "Current_Time",
To_char(TABLE2.time_stamp, 'MM-DD-YYYY HH24:MI:SS') as "Recorded_Time"
FROM TABLE1 TABLE1 LEFT OUTER JOIN TABLE2 TABLE2 ON TABLE1.OUT_NO = TABLE2.OUT_NO
WHERE TABLE1.OUT_NO > '12345'
I need to subtract Current_time - Recorded_Time and get result in Hours and Minutes.
how can I achieve this?
Simply subtract one from the other
select sysdate - systimestamp from dual;
Ensure that they're still a DATE and a TIMESTAMP, do not convert them to characters first. This returns an INTERVAL datatype.
Apparently this is giving you an integer, which means your timestamp is being implicitly converted to a date (or is in fact already a date and not a timestamp).
If this is the case you have the number of days between the two dates; multiply by the number of minutes in a day in order to get this in minutes:
select ( sysdate - systimestamp ) * 60 * 24 from dual;
use datediff() built-in function
SELECT
TABLE1.OUT_NO,
To_char(sysdate, 'MM-DD-YYYY HH24:MI:SS') as "Current_Time",
To_char(TABLE2.time_stamp, 'MM-DD-YYYY HH24:MI:SS') as "Recorded_Time",
datediff(mi,time_stamp,getdate()) as DiffInTime
FROM TABLE1 TABLE1 LEFT OUTER JOIN TABLE2 TABLE2 ON TABLE1.OUT_NO = TABLE2.OUT_NO
WHERE TABLE1.OUT_NO > '12345'
will show results in minutes. Dance from there.

Oracle Timestamp Conversion with Dates

Assuming this has a simple solution, but I can't find it.
I'm trying to do some logic on a DATE field in Oracle. My desire is to take a DATE field and subtract X hours from it.
For instance: SELECT A.MyDATE - 100 Hours from dual;
however, I need a result in a timestamp format 'YYYY-MM-DD hh:mm'.
I've tried CAST(A.MyDATE as TIMESTAMP) - NUMTODSINTERVAL(100/24,'day') however it didn't work.
I found out that the issue is that the MyDATE field when cast to a timestamp still contained some residual time elements. How can I reset these??
Thanks!
You can just do this with subtraction:
select a.MyDate - 100.0/24
To convert to varchar:
select to_char(a.MyDate - 100.0/24, 'YYYY-MM-DD')
And, if you want to get rid of that pesky time on the date:
select trunc(a.MyDate - 100.0/24) as JustTheDate
The formats and dates in my example can be changed to any other formats and dates:
SELECT To_Timestamp(To_Char(Sysdate - INTERVAL '100' HOUR, 'MM/DD/YYYY HH24:MI'), 'MM/DD/YYYY HH24:MI')
FROM dual
/
Output:
2/4/2013 10:18:00.000000000 AM
To remove time element add Trunc() to any of your dates...:
SELECT Trunc(To_Timestamp(To_Char(Sysdate - INTERVAL '100' HOUR, 'MM/DD/YYYY HH24:MI'), 'MM/DD/YYYY HH24:MI'))
FROM dual
/
Output: 2/4/2013
Conversion/Casting - when using other dates in place of sysdate then add formats as in my other examples:
SELECT CAST(SYSDATE AS TIMESTAMP) - INTERVAL '100' HOUR FROM dual
/
Output: 2/4/2013 10:26:35.000000000 AM
SELECT start_date tstamp_to_date, CAST(start_date AS timestamp) date_to_tstamp FROM
(
SELECT to_date(to_char(to_timestamp ('2013-02-07 10:07:47.000' , 'YYYY-MM-DD HH24:MI:SS.FF'),'DD-MON-YYYY HH24:MI:SS'), 'DD-MON-YYYY HH24:MI:SS') start_date
FROM dual
)
/
Output:
tstamp_to_date date_to_tstamp
-------------------------------------------------------
2/7/2013 10:07:47 AM 2/7/2013 10:07:47.000000 AM
In Oracle, a DATE always has a day and a time component. Depending on the tool you are using and your session's NLS_DATE_FORMAT, it is entirely possible that the tool may not display the time component when you look at the data. But that is simply a display question, it has no impact on the actual data.
If you want to subtract 100 hours from midnight on the day that MyDate represents
SELECT TRUNC(MyDate) - interval '100' hour
FROM dual
This will return a DATE. If you want to return a string in a particular format
SELECT TO_CHAR( TRUNC(MyDate) - interval '100' hour, 'YYYY-MM-DD hh:mi am' )
FROM dual
Note that I'm assuming that there was a typo in your question. I assume that you want to display the minutes after the hour (mi) rather than the month (mm).
I am trying to fetch the records which is older than 30 days (from Mod_date) and I am using the below query and it is returning all the data and I want only 30 days old data.
Sample :- Mod_date 03-NOV-12 12.00.00.000000000 AM
Query :-
select Mod_date from fil_cnfact where Mod_date <= sysdate -30 order by Mod_date asc ;