I am writing the query like
select * from tablename where date between '27-mar-2015' and '1-apr-2015'.
but records with date '1-apr-2015' is not retrieved from the oracle database date type is TIMESTAMP(6).
between '27-mar-2015' and '1-apr-2015'
'27-mar-2015' is NOT a DATE, it is a string literal. You are forcing Oracle to do an implicit datatype conversion.
date type is TIMESTAMP(6)
Since your data type is TIMESTAMP, you need to take care of the precision of the TIMESTAMP datatype which holds fractions of a second to a precision between 0 and 9 decimal places, the default being 6.
BETWEEN
to_timestamp('27-mar-2015 01.01.01.000001','dd-mon-yyyy HH24:MI:SS.FF')
AND
to_timestamp('01-apr-2015 23.59.59.999999','dd-mon-yyyy HH24:MI:SS.FF')
For example,
SQL> ALTER SESSION SET nls_timestamp_tz_format = 'DD-MON-YYYY HH24:MI:SS.FF';
Session altered.
SQL> SELECT
2 to_timestamp('27-mar-2015 01.01.01.000001','dd-mon-yyyy HH24:MI:SS.FF') st,
3 to_timestamp('01-apr-2015 23.59.59.999999','dd-mon-yyyy HH24:MI:SS.FF') end
4 FROM dual
5 /
ST END
---------------------------------- ----------------------------------
27-MAR-15 01.01.01.000001000 AM 01-APR-15 11.59.59.999999000 PM
SQL>
You have to note that timestamp-columns (and with oracle even date-columns) always include the time of day and that date '1-apr-2015' actually means '1-apr-2015 00:00:00' - then everything makes sense. The exact string-representation of timestamps might vary according to the configured locale.
To get date including the first of april you best use between ... and '2-apr-2015' if you don't mind having the first microsecond of that day included.
Try convert to_date:
select * from tablename
where date between to_Date('27-mar-2015','dd-mm-yyy')
and to_date('1-apr-2015','dd-mm-yyyy')
I have faced same issue. Using TRUNC Date Function helped.
select * from tablename where trunc(date,'DAY') between '27-mar-2015' and '1-apr-2015'
Try to use this code:
select * from tablename where to_date(date,'DD-MON-YYYY') between '27-mar-2015' and '1-apr-2015'.
Related
According to the H2 documentation, in the Oracle compatibility mode:
DATE data type is treated like TIMESTAMP(0) data type.
Meantime, DATE and TIMESTAMP(0) datatypes are not the same in Oracle. Compare:
SELECT CAST(SYSDATE AS TIMESTAMP(0)), CAST(SYSDATE AS DATE) from dual
gives
25-MAR-22 13.07.42.000000000 25-MAR-22
respectively.
In particular, this weird treating of DATE as TIMESTAMP(0) influences on how H2 calculates the difference between two dates.
Again, in Oracle:
SELECT CAST(TO_DATE('2022-01-05', 'YYYY-MM-DD') AS TIMESTAMP(0)) - CAST(TO_DATE('2022-01-01', 'YYYY-MM-DD') AS TIMESTAMP(0)) from dual
gives
+04 00:00:00.000000
and
SELECT CAST(TO_DATE('2022-01-05', 'YYYY-MM-DD') AS DATE) - CAST(TO_DATE('2022-01-01', 'YYYY-MM-DD') AS DATE) from dual
produces just:
4
Apparently, for H2 both above queries produce the result in nanoseconds and not days as expected.
So, it is an H2 bug or I am missing something?
Meantime, DATE and TIMESTAMP(0) datatypes are not the same in Oracle
Oracle differs from many other RDBMS in that its DATE data type ALWAYS contains both a date and a time component. Its implementation predates the ANSI standard.
In Oracle, if you have the table:
CREATE TABLE table_name (ts TIMESTAMP(0), dt DATE);
and insert the data:
INSERT INTO table_name (ts, dt) VALUES (SYSDATE, SYSDATE);
Then you can look at the binary data being stored using the DUMP function:
SELECT DUMP(ts) AS dump_ts,
DUMP(dt) AS dump_dt
FROM table_name;
Which outputs:
DUMP_TS
DUMP_DT
Typ=180 Len=7: 120,122,3,25,15,13,37
Typ=12 Len=7: 120,122,3,25,15,13,37
Then you can see that they are both stored as 7-byte binary values:
120 = Century + 100
122 = Year-of-century + 100
3 = Month
25 = Day
15 = Hour + 1
13 = Minutes + 1
37 = Seconds + 1
And the binary values are identical (the only difference is in the meta-data Typ where 180 = TIMESTAMP and 12 = DATE).
Effectively, they are stored identically.
db<>fiddle here
However
The side-effects of a TIMESTAMP vs. a DATE data type in Oracle may lead to different effects.
When you subtract a TIMESTAMP and either a TIMESTAMP or a DATE then the return value is an INTERVAL DAY TO SECOND data type.
When you subtract a DATE and a DATE then the default return value is a NUMBER representing the number of days difference.
When you display a TIMESTAMP then the client application you are using may default to using the NLS_TIMESTAMP_FORMAT session parameter to format the timestamp as a string and the default for this parameter will typically show date, time and fractional seconds.
When you display a DATE then the client application you are using may default to using the NLS_DATE_FORMAT session parameter to format the date as a string and the default for this parameter will show date but not time (and there will never be any fractional seconds to show). Just because the client application may chose not to show the time component does not mean that the time component does not exist.
If you set the session parameters using:
ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
ALTER SESSION SET NLS_TIMESTAMP_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
Then, provided your client application is using those parameters to format them, they will display identically.
The problem you are seeing with the difference in Oracle is due to these side effects.
If the question is
So, it is an H2 bug or I am missing something?
than the the answer would be:
No, it is not a bug, and what you've missed is the fact, that compatibility modes in H2 are just that - attempt to reach with minimal efforts maximum compatibility with different databases.
H2 is not an emulator for any non-standard features (quirks) of those databases.
It that particular case, to achieve identical behaviour would require to introduce new non-standard data type, which goes beyond "minimal effort" level.
The different in the output of the values in the first query is down to the session's NLS settings. These control the display format for dates and timestamps:
sho parameter nls_date_format
NAME TYPE VALUE
--------------- ------ -----------
nls_date_format string DD-MON-YYYY
sho parameter nls_timestamp_format
NAME TYPE VALUE
-------------------- ------ -------------------------
nls_timestamp_format string DD-MON-YYYY HH24.MI.SSXFF
SELECT CAST(SYSDATE AS TIMESTAMP(0)), CAST(SYSDATE AS DATE) from dual;
CAST(SYSDATEASTIMESTAMP(0)) CAST(SYSDAT
------------------------------ -----------
25-MAR-2022 12.18.24.000000000 25-MAR-2022
If you change these to be the same format, both expressions return the same result:
alter session set nls_date_format = 'DD-MON-YYYY HH24:MI:SS';
alter session set nls_timestamp_format = 'DD-MON-YYYY HH24:MI:SS';
SELECT CAST(SYSDATE AS TIMESTAMP(0)), CAST(SYSDATE AS DATE) from dual;
CAST(SYSDATEASTIMEST CAST(SYSDATEASDATE)
-------------------- --------------------
25-MAR-2022 12:17:43 25-MAR-2022 12:17:43
So they both contain the full date + time with no fractional seconds.
Note that while date and timestamp(0) have the same precision, as your further examples show they work differently:
Subtracting one date from another returns the number of days between the values as a number
Subtracting a timestamp from a date or timestamp returns an interval
So the result of:
SELECT CAST(TO_DATE('2022-01-05', 'YYYY-MM-DD') AS DATE) - CAST(TO_DATE('2022-01-01', 'YYYY-MM-DD') AS DATE) from dual
Is 4 days.
I'm just trying to fetch Hour of my table from created date in Oracle 12c Database but it is showing error INVALID EXTRACT FIELD FOR EXTRACT FIELD. kindly guide me to fetch hour of my date my code is here...
SELECT
EXTRACT( HOUR FROM (TO_CHAR(CREATED_DATE,'RRRR-MM-DD HH:MI:SS')) ) HOUR
FROM
INVOICE_V;
my Date is stored as 6/1/2020 4:04:50 PM in this format and Extract function is not accept this function.
Do not store dates as strings.
But, since you have, convert it from a string to a date using TO_DATE:
SELECT EXTRACT( HOUR FROM TO_TIMESTAMP(CREATED_DATE,'DD/MM/YYYY HH12:MI:SS AM') ) AS HOUR
FROM INVOICE_V;
If, however, you meant that its just displaying in that format (and is actually a DATE data type) then CAST the date to a timestamp:
SELECT EXTRACT( HOUR FROM CAST( CREATED_DATE AS TIMESTAMP) ) AS HOUR
FROM INVOICE_V;
An hour can not be used in the EXTRACT function.
The only way to extract hour is to use TO_CHAR or subtract it from TRUNC date as follows:
TO_CHAR(created_date,'HH24') -- OR 'HH' as per your requirement
-- OR
FLOOR(24*(created_date- TRUNC(created_date)))
Please note that Oracle does not store dates in any format. It has its own binary representation. What you see while selecting from the table is based on the NLS_DATE_FORMAT parameter.
You can set it according to your requirement.
ALTER SESSION SET NLS_dATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS'; -- like this
If you have a date column (or the-like), then:
select extract(hour from cast(created_date as timestamp)) as hr
from invoice_v
Alternatively:
select to_char(created_date, 'hh24') as hr
from invoice_v
The first expression returns an integer number, while the second produces a string.
Note that hour is a language keyword, hence not a good choice for an identifier (here, you used it as a column alias). I changed that.
Why does below query work successfully?
select to_char(sysdate,'MM-YYYY') from dual;
But the following queries give an invalid number error:
select to_char('28-JUL-17','MM-YYYY') from dual;
select to_char('7/28/2017','MM-YYYY') from dual;
Though, below query gives you the same date format.
select sysdate from dual; -- 7/28/2017 11:29:01 AM
TO_CHAR function accepts only date or number. Maybe you can try this
select to_char(to_date('28-JUL-17', 'DD-MON-YY'),'MM-YYYY') from dual;
As a side note, if you're planning to convert a bunch of dates to strings so you can look for all records in a certain month of a certain year, be aware that the TRUNC function can be used to reduce the precision of a date (e.g. to "month and year"). The following query pulls all records created this month, from the table. It should be faster than converting dates to char and doing string comparison..
SELECT * FROM table WHERE trunc(create_date, 'MON') = trunc(sysdate, 'MON')
Because function TO_CHAR() accepts date or timestamp values. However, neither '28-JUL-17' nor '7/28/2017' are dates or timestamps - they are STRINGS.
Oracle gently tries to convert these stings into DATE values. This implicit conversion may work or may fail, it depends on your current session NLS_DATE_FORMAT, resp. NLS_TIMESTAMP_FORMAT settings.
As given already in other answers you have to convert the string explicitly:
TO_DATE('28-JUL-17', 'DD-MON-RR')
TO_DATE('7/28/2017', 'MM/DD/YYYY')
to_char() isn't expecting you to start with a char value. If you really want that to work, you'll need to wrap it around a to_date() function.
to_char(
to_date(
'28-JUL-17'
, 'DD-Mon-YY'
)
,'MM-YYYY'
)
You are using an incorrect mask, for more information read here.
The correct one should be:
select to_char(to_date('28-JUL-17','DD-MON-YY'), 'MON-YY') from dual;
You can also extract the month using EXTRACT:
select EXTRACT (MONTH FROM to_date('28-JUL-17','DD-MON-YY')) from dual;
Cheers
I'm trying to set a value in an Oracle database that resembles the following:
2016-06-21 03:07:25.0
It is a varchar of the current date with one digit after the decimal for seconds. I tried multiple ways to achieve this but to no avail:
SQL> select sysdate from dual;
SYSDATE
--------
21-06-16
From this I tried:
SQL> alter session set nls_date_format='YYYY-MM-DD HH24:MI:SS.F';
ERROR:
ORA-01821: date format not recognized
SQL> alter session set nls_date_format='YYYY-MM-DD HH24:MI:SS.s';
ERROR:
ORA-01821: date format not recognized
Then I tried:
SQL> SELECT TO_CHAR(SYSDATE,'YYYY-MM-DD HH24:MI:SS') FROM dual;
TO_CHAR(SYSDATE,'YY
-------------------
2016-06-21 12:58:55
Since that worked up to the seconds I tried the decimal part:
SQL> SELECT TO_CHAR(SYSDATE,'YYYY-MM-DD HH24:MI:SS.SSSS') from dual;
TO_CHAR(SYSDATE,'YYYY-MM
------------------------
2016-06-21 13:23:47.4747
So I can get 4 significant places. Now I try with just 1:
SQL> SELECT TO_CHAR(SYSDATE,'YYYY-MM-DD HH24:MI:SS.S') from dual;
SELECT TO_CHAR(SYSDATE,'YYYY-MM-DD HH24:MI:SS.S') from dual
*
ERROR at line 1:
ORA-01821: date format not recognized
So how can I get the current timestamp in the abovementioned format with seconds set to one decimal place?
SSSS isn't fractional seconds. It's just repeating the SS value twice; in your example you get 13:23:47.4747 - the 4747 is just 47 displayed twice. Maybe you were thinking of SSSSS, but that is the number of seconds since midnight (i.e. 0-86399) so isn't useful here either. A single S isn't a valid format model element.
Dates don't have fractional second precision. A single F isn't a valid format model element either, but even FF isn't valid for a date.
You need to use systimestamp to get the server time with fractional seconds, rather than sysdate:
select to_char(systimestamp, 'YYYY-MM-DD HH24:MI:SS.FF1') from dual;
TO_CHAR(SYSTIMESTAMP,'YYYY-MM
-----------------------------
2016-06-21 14:42:22.7
Storing a date/time as a string is generally a bad idea. I'd suggest you make the column timestamp(1) which will keep the one-decimal-place precision when you set it from systimestamp. You can see what it would get with cast:
select to_char(cast(systimestamp as timestamp(1)), 'YYYY-MM-DD HH24:MI:SS.FF9') from dual;
TO_CHAR(CAST(SYSTIMESTAMPASTI
-----------------------------
2016-06-21 14:49:09.900000000
Converting a date/time to a string should really only be done for display, not for storage.
I was trying to select some data from my table using the following query:
select * from table1 where column1 = to_date('14-05-14','yy-mm-dd');
Where the column data type is DATE. I observed that, the above query won't return anything unless we modified it as,
select * from table1 where trunc(column1) = to_date('14-05-14','yy-mm-dd');
even though there are records available.
I checked the documentation for TRUNC.Can anyone please explain why this happens?
UPDATE
As per the valuable comments I think some time values may also associated with the DATE. But I cannot view/edit that time. How can I ensure there are time values associated.
Both TO_DATE and TRUNC are different. See the below example.
SQL> ALTER SESSION SET nls_date_format = 'dd/mm/yyyy hh24:mi:ss';
Session altered.
SQL> SELECT TO_DATE(SYSDATE) FROM DUAL;
TO_DATE(SYSDATE)
-------------------
28/05/2014 16:03:25
SQL> SELECT TRUNC(SYSDATE) FROM DUAL;
TRUNC(SYSDATE)
-------------------
28/05/2014 00:00:00
In Your first query to_date('14-05-14','yy-mm-dd') is comparing with the date field column1 in your table which has time values also. Whereas in Your 2nd query You are truncating the time part from table data and from Your query, that's why it's matching.
The DATE datatype stores the year (including the century), the month, the day, the hours, the minutes, and the seconds (after midnight).
TRUNC function will truncate the date to the day value, so that any hours, minutes, or seconds will be truncated off.
For more info please look at these below links
http://docs.oracle.com/cd/B28359_01/server.111/b28318/datatype.htm#CNCPT413
http://www.techonthenet.com/oracle/functions/trunc_date.php