I've got a question about date function on oracle.
I have the following table
statistic_table(
pages AS varchar(10),
date_created AS date
);
I have the following sql
SELECT COUNT(*) FROM statistic_table WHERE date_created BETWEEN sysdate-5 AND sysdate-1
and
SELECT COUNT(*) FROM statistic_table WHERE date_created BETWEEN to_date('12-AUG-2011') AND to_date('16-AUG-2011');
the question is, why is it return different numbers. assuming sysdate-5 returns 12-aug-2011 and sysdate-1 returns 16-aug-2011
Any help would be much appreciated!
Cheers,
sysdate - 5 will give you a date with the current time. So if I ran it at 1pm precisely, the query would be equivalent to:
select (*)
FROM statistic_table
WHERE date_created BETWEEN to_date('12-Aug-2011 13:00:00')
AND to_date('16-Aug-2011 13:00:00')
whereas the second query is:
select (*)
FROM statistic_table
WHERE date_created BETWEEN to_date('12-Aug-2011 00:00:00')
AND to_date('16-Aug-2011 00:00:00')
you should probably try this instead:
select (*)
FROM statistic_table
WHERE date_created BETWEEN trunc(sysdate) -5
AND trunc(sysdate) -1
A date in Oracle is a point in time with a precision of a second.
SYSDATE returns the current date and time and is therefore not the same as to_date('17-AUG-2011'):
SQL> SELECT to_char(sysdate, 'dd-mon-yyyy hh24:mi:ss') FROM DUAL;
TO_CHAR(SYSDATE,'DD-MON-YYYYHH
------------------------------
17-aug-2011 15:52:13
Use the TRUNC function if you only want the date component:
SQL> SELECT to_char(trunc(sysdate), 'dd-mon-yyyy hh24:mi:ss') FROM DUAL;
TO_CHAR(TRUNC(SYSDATE),'DD-MON
------------------------------
17-aou-2011 00:00:00
Because SYSDATE includes a time component, so if the current time is 11:22:33, then
SELECT COUNT(*) FROM statistic_table
WHERE date_created BETWEEN sysdate-5 AND sysdate-1
is actually equivalent to
SELECT COUNT(*) FROM statistic_table
WHERE date_created BETWEEN to_date('12-AUG-2011 11:22:33','DD-MON-YYYY HH24:MI:SS')
AND to_date('16-AUG-2011 11:22:33','DD-MON-YYYY HH24:MI:SS')
To avoid the time component do this:
SELECT COUNT(*) FROM statistic_table
WHERE date_created BETWEEN TRUNC(sysdate)-5 AND TRUNC(sysdate)-1
An Oracle DATE always has a day and a time component.
sysdate-5 returns a date exactly 5 days ago. If today is August 17 at 10 AM, for example, sysdate-5 returns August 12 at 10 AM.
to_date('12-AUG-2011', 'DD-MON-YYYY'), on the other hand, returns August 12 at midnight. So it returns a date that is 10 hours earlier than sysdate-5.
sysdate auto returns with a time component as mentioned by the previous answers.
When using to_date it is converting a string to a date. With this being said you can pass in parameters to make it return the same thing.
Have a look at this link that explains it.
to_date parameters
Related
What is the query in Oracle to fetch the data for current_date
the column end_date is like the following
end_date
27-10-16 03:35:00.000000000 PM
23-11-16 11:15:00.000000000 AM
02-11-16 03:00:00.000000000 PM
08-11-16 09:00:00.000000000 AM
Like I am running the following query as
Select * from table1
where end_date < TO_DATE('2017-04-11 00:00:00', 'YYYY-MM-DD HH24:MI:SS')
it is running successfully, but when i replace the query with the current date ... it is not giving the results
Select * from table1
where end_date < TO_DATE(current_date, 'YYYY-MM-DD HH24:MI:SS')
could someone tell me what is the cause the second query is not giving results.
CURRENT_DATE returns date. There is no need to use TO_DATE. The below query should be enough.
Select * from table1
where end_date < current_date;
If you run the below query you'll understand what went wrong for you. Year becomes 0011.
SELECT TO_DATE(current_date, 'YYYY-MM-DD HH24:MI:SS') FROM DUAL;
Please note that CURRENT_DATE returns the current date in the session time zone. SYSDATE returns the current date and time set for the operating system on which the database resides. This means that CURRENT_DATE and SYSDATE can return different results. You can have a look at this
The query worked like this :
Select * from table1
where trunc(end_date) < trunc(sysdate)
Trunc is used to compare the both dates and it fetch the results.
CURRENT_DATE is already a DATE value. You can format the output using to_char if you want.
end_date < CURRENT_DATE should do the job. Or you can set the nls parameter accordingly for a better readability.
If you are comparing only date, without timestamp, you can go with trunc()
i have 28-APR-2016 10:05:07 date as parameter in stored procedure. This may be the current time also as string date.
i need to set the time to 9 am to check the shift start timing.
SELECT TO_DATE('28-APR-2016 10:05:07', 'DD-MON-YYYY HH24:MI:SS') FROM dual;
I am new to oracle. Help is appreciated.
If you want the date with 9:00 a.m., then you can do:
SELECT TRUNC(TO_DATE('28-APR-2016 10:05:07', 'DD-MON-YYYY HH24:MI:SS')) + 9/24.0
FROM dual;
You can also use:
SELECT TRUNC(TO_DATE('28-APR-2016 10:05:07', 'DD-MON-YYYY HH24:MI:SS')) + INTERVAL '9' HOUR
FROM dual;
I'm just old-fashioned so I tend to use the first method.
select TO_CHAR(to_date(sysdate, 'DD-MON-YYYY'), 'DAY') FROM DUAL;
When I run this query the output was : SUNDAY. But we know today is Tuesday(1-1-2013).
And
then changed the query as
select TO_CHAR(to_date('01-JAN-2013', 'DD-MON-YYYY'), 'DAY') FROM DUAL;
answer was :TUESDAY.
then Changed query as
select TO_CHAR(to_date(sysdate+1, 'DD-MON-YYYY'), 'DAY') FROM DUAL;
answer is :MONDAY.
When I using the sysdate why it is show SUNDAY as output?
I am new in oracle db. Please help me.
use this:
select TO_CHAR(sysdate, 'DAY') FROM DUAL;
you are using this :
to_date(sysdate, 'DD-MON-YYYY')
which is giving you date=1/1/0013 which is sunday
Please refer the documentation for sysdate here. Sysdate is already a date data type.
Your example query is inappropriate as to_date function takes first parameter as String not date.
Try the simple query below:
select TO_CHAR(sysdate, 'DAY') FROM DUAL;
This should return TUESDAY as output.
To_date is used to convert a strin to date. As sysdate is already a date, one must not add add to_date.
I have a column named date_col of data-type date. What's wrong with this query?
update test set date_col = to_date(sysdate,'DD-Mon-YYYY HH24:MI:SS')
Only date mon and yy is visible. not the time.
How can I make it work?
SYSDATE is yet a date. You don't need to cast SYSDATE to date type because it is a date_
update test
set date_col = sysdate
To see time fraction use to_char:
select to_char(date_col, 'HH24 MI')
from test;
I have the following strange problem in Oracle
(Please keep in mind that I have little experience in SQL and even less in Oracle).
If I do this:
SELECT TO_CHAR(sysdate, 'YYYY-MM-DD HH24:MI') FROM dual
I get this:
2010-12-02 18:39
All fine there.
However, if I do this:
UPDATE favorite_item
SET favorite_item.last_used_date = TO_DATE(sysdate, 'YYYY-MM-DD HH24:MI')
WHERE favorite_item.favorite_item_id = 1
I get this in my database:
10-DEC-02
Which is the 10th of December '02 which is not correct
If I do this to confirm:
SELECT TO_CHAR(favorite_item.last_used_date, 'YYYY-MM-DD HH24:MI') AS last_used_date
FROM favorite_item
WHERE favorite_item.favorite_item_id = 1
I get this:
0002-12-10 00:00
Which is completely wrong.
What am I doing wrong? I feel that the date setting is not working correctly.
Thanks in advance for your help.
Don't use TO_DATE() on sysdate; sysdate is already a date.
UPDATE favorite_item
SET favorite_item.last_used_date = sysdate
WHERE favorite_item.favorite_item_id = 1`
The problem is using the to_date() function on anything other than a string.
As to why you are getting the wrong results, there is an internal conversion that happens when you use to_date on a date. Since to_date actually takes input as a string, your date is initially converted into a string (according to your NLS_DATE_FORMAT setting) and then converted back to a date. Hence the mismatch.
SQL> select sysdate from dual;
SYSDATE
---------
02-DEC-10
SQL> select to_date(sysdate,'YYYY-MM-DD') from dual;
TO_DATE(S
---------
10-DEC-02
--- This is because, the above string is actually executed as
SQL> select to_date(
to_char('02-DEC-10','YYYY-MM-DD') from dual;
TO_DATE('
---------
10-DEC-02
SQL> select to_date(
2 /* implicit conversion... dd-mon-yy' is my session's NLS_DATE_FORMAT */
3 to_char(sysdate,'dd-mon-yy'),
4 'YYYY-MM-DD')
5 from dual;
TO_DATE(/
---------
10-DEC-02
sysdate returns a date, so converting it to a date using to_date(sysdate, ...) is redundant/not necessary. You're getting that odd result because the date is being cast to a string by the to_date function using the Oracle default of "DD-MON-YY" and then back into a date using your supplied format, "YYYY-MM-DD". Since the formats don't match, Oracle is interpreting the year as the day and the day as the year. This works correctly (but, again, is redundant):
select to_date(sysdate, 'DD-MON-YY') from dual;