Oracle - Date Format - oracle

I need your assistance with converting Oracle dates.
I have a column that stores dates like this 20150731 00:00:34.220. However, I would like to show the column like this 20150731 but when I run a simple select statement to test output I get the following error.
select TO_DATE('20150731 00:00:34.550','YYYYMMDD')
from dual
Error
ORA-01830: date format picture ends before converting entire input string

This query
select TO_DATE('20150731 00:00:34.550','YYYYMMDD')
from dual
leads to error
ORA-01830: date format picture ends before converting entire input string
because you pass string with length 22 characters, but at the same time you pass date format with 8 characters, which obviously doesn't correspond to string. You should write the query as
select to_timestamp('20150731 00:00:34.550','yyyymmdd hh24:mi:ss.ff3')
from dual
As for your table, since you have varchar2 column with dates, you have to take care about table content. Query requires exect matching of the source string and date format.
If you want to show only date without time and you don't need to process this string as date, you can make just
select substr('20150731 00:00:34.550', 1, 8)
from dual

What is the data type of the column? If it is DATE (as it should be) then not it is not stored in the format you say. It is stored in an internal binary format. You would/should use the to_char function to DISPLAY it in whatever format you choose. If you do not use the to_char function, it will be displayed in the format specified by NLS_DATE_FORMAT, which can be specified at several locations.
As for your example, you passed a string format of yyyymmd hh:mi:ss.fff', but you provided a description mask of only YYYYMMDD. It doesn't know what to do with time component. In addition to that when you SELECT TO_DATE, oracle also has to do an implied TO_CHAR to convert it back to a string for display purposes.
In addition, you provided your to_date with a character string that included fractions of seconds. A DATE data type only resolves to seconds. If you need fractional seconds, you need to use TIMESTAMP, not DATE.

If your column is a varchar and you need a date output:
select TO_DATE(substr('20150731 00:00:34.550', 1, 8),'YYYYMMDD') from dual
If it's in a date format and you need a string output:
select to_char(your_column, 'YYYYMMDD') from your_table

Is that being stored in an Oracle datetime column? If not, you may have to do some manipulation to get it into a DD-MON-YYYY format. If it is being stored as a text string you could use SUBSTR( Date_field, Start_Position, Length) to get the first 8 characters. check out this link SUBSTR

Working on the assumption that you're not trying to change the value in the column, and are just trying to show it in the YYYYMMDD format -
As mentioned by a_horse_with_no_name, you'll just need to convert it to a character string. In this example I used systimestamp as my date:
SELECT TO_CHAR(systimestamp,'YYYYMMDD') FROM DUAL
Result:
20160121
That should give you the YYYYMMDD format you want to display.

Related

How to make a constraint on DATE FORMAT in ORACLE

say my usual Date format is '14-jan-2019' and i want my date to only be accepted as 'YYYY-MM-DD' how do i do that? and can i change jan to an actual number?
In my opinion, the right / correct way to do that is to declare your date column (or variable or whatever it is) as DATE, e.g.
create table test (date_column date);
or
declare
l_date_variable date;
begin
...
Doing so, you'd let the database take care about valid values.
You'd then be able to enter data any way you want, using any valid date format mask, e.g.
to_date('06.01.2020', 'dd.mm.yyyy')
date '2020-01-06'
to_date('2020-06-01', 'yyyy-dd-mm')
etc. - all those values would be valid.
A DATE data type has no format - it is stored internally as 7-bytes representing year (2 bytes) and month, day, hour, minute and second (1 byte each).
'14-JAN-2019' is not a date - it is a text literal.
If you want to store date values then use a DATE data type.
If you want to only accept strings of a specific format as input then in whatever user interface you use to talk to the database then accept only that format. If you are converting strings to DATEs and wanting an exact format then you can use:
TO_DATE( '2019-01-14', 'fxYYYY-MM-DD' )
Note: the fx format model will mean that the exact format is expected and the typical string-to-date conversion rules will not be applied.

Storing timestamp values stored in a varchar2 column into a date column in oracle

I have a column in a table that stores timestamp values as
"2018-01-12 16:13:51.107000000", i need to insert this column into a date column in another table, what format mask do i have to use here..
I have used the mask 'YYYY-MM-DD HH24:MI:SS.FF' but shows 'date format not recognized'.
I am assuming that you were trying to use TO_DATE on your text timestamp data. This won't work, because Oracle dates do not store anything more precise than seconds. Since your timestamps have fractional seconds, you may use TO_TIMESTAMP here, then cast that actual timestamp to a date:
SELECT
CAST(TO_TIMESTAMP('2018-01-12 16:13:51.100000',
'YYYY-MM-DD HH24:MI:SS.FF') AS DATE)
FROM dual;
12.01.2018 16:13:51
Demo
You can do this with a single call to TO_DATE(), but you must give the correct format model. Note that this solution is simpler (and possibly faster - if that matters) than converting to a timestamp and then casting to date.
If you want TO_DATE() to ignore part of the input string, you can use the "boilerplate text" syntax in the format model. That is enclosed in double quotes. For example, if your string included the letter T somewhere and it had to be ignored, you would include "T" in the same position in the format model.
This has some flexibility. In your case, you must ignore the decimal point, and up to nine decimal digits (the maximum for timestamp in Oracle). The format model will allow you to use ".999999999" (or any other digits, but 9999... is used by most programmers) to ignore a decimal point and UP TO nine digits after that.
Demo: (notice the double-quoted "boilerplate text" in the format model)
select to_date('2018-01-12 16:13:51.100000',
'YYYY-MM-DD HH24:MI:SS".999999999"') as dt
from dual;
DT
-------------------
2018-01-12 16:13:51

Date Conversion in Oracle (YYYYMMDD format back to YYYYMMDD)

Hi I am pretty much new to Oracle and need an idea on how to do it.
Consideer I have a Text file and the value in the file is
'20180924'
'20180923'
I read these value from the Pro*c and then I add 29 days to it, so the value now changes from 20180924 to 20180953. I don't want that to happen i want the value to be added as
TO_DATE('20180924','yyyymmdd')+29 which returns the value as "23-OCT-18"
The answer is correct but i want the result to also be in the same YYYYMMDD format like 20181023.
How do i achieve this ?
Just format it back.
to_char(TO_DATE('20180924','yyyymmdd')+29, 'yyyymmdd')
Dates do not have a format - they are represented internally by 7 or 8 bytes.
If you want a date to have a format then you will need to convert it to a data type that can be formatted - i.e. a string:
TO_CHAR( TO_DATE( '20180924', 'yyyymmdd' ) + 29, 'YYYYMMDD' )
When SQL/Plus (or SQL Developer) displays date data types they implicitly convert them to strings (since this is more meaningful to you, the user, than displaying the raw bytes) and uses the NLS_DATE_FORMAT session parameter as the format model in this implicit conversion. If you want to change this then you can use:
ALTER SESSION SET NLS_DATE_FORMAT = 'YYYYMMDD';
and then your query:
TO_DATE( '20180924', 'yyyymmdd' ) + 29
should (provided your SQL client uses this setting and does not have their own internal format preferences) give the output you expect. (Note: this will change the default format for the client to display all dates in this session and not just this one statement.)
select TO_NUMBER((TO_CHAR(TO_DATE(HIREDATE,'DD-MON-YY'),'YYYYMMDD')) FROM EMP;
select TO_NUMBER((TO_CHAR(TO_DATE(HIREDATE,'DD-MON-YY'),'YYYYMMDD'))FROM EMP
20201101
select TO_NUMBER((TO_CHAR(TO_DATE(SYSDATE,'DD-MON-YY'),'YYYYMMDD')) FROM DUAL;

wrong date format in bi reports oracle

I have the following date which is in varchar2(11) column in database:
select valid_untill from SALES_ORDERS_V where header_id = 7999410;
30-May-2016
Using rtf template and xml source, the report output (PDF) is:
4950-11-19 04:45:49:0
I don't know its equal to "30-May-2016".
Why this is showing this, as I did not do any formating in rtf?
Not familiar with either RTF or XML-Publisher, but whenever you retrieve a date saved in string format, IF you use it as a date in your code and not as a string, you must make sure you retrieve it correctly.
In this case, with your select statement: it shouldn't be select valid-until from... (or is it really misspelled, with two l at the end: valid_until?) If it is meant to be used as a date, it should be
select to_date(valid_until, 'dd-Mon-yyyy') from ...
Really the problem here is that the date is stored as a string and not in the date datatype. Good luck!

Oracle date comparison as string and as date

1) Why is that this doesn't works
select * from table where trunc(field1)=to_date('25-AUG-15','DD-MON-YY');
select * from table where trunc(field1)=to_date('25/Aug/15','DD/MON/YY');
row is returned in above cases.
So, does this mean that no matter what format the date is there in field1, if it is the valid date and matches with 25th August, it will be returned ( it won't care what format specifier we specify at the right side of the query i.e. DD-MON-YY or DD/MON/YY or anything else) ?
2) but comparsion as string exactly works:
select * from table where to_char(field1)=to_char(to_date
('25/AUG/15','DD/MON/YY'), 'DD/MON/YY');
no row is returned as the comparison is performed exactly.
I have field1 as '25-AUG-15' ( although it can be viewed differently doing alter session NLS_DATE_FORMAT...)
field1 is of DATE type
Any help in understanding this is appreciated specifically with respect to point 1
The DATE data type does not have format -- it's simply a number. So, a DATE 25-Aug-2015 is the same as DATE 25/AUG/15, as well as DATE 2015-08-15, because it's the same DATE.
Strings, on the other hand, are collections of characters, so '25-Aug-2015' is obviously different from '25/AUG/15'.
In the first example you are comparing DATE values. In the second example you are comparing strings.
So you have a field of type DATE with value of The 25th of August 2015,
but it could be visualized in different ways, what in fact is named format.
The DATE has format!
The DATE has implicit format defined by Oracle, in your case it is DD-MON-YY, because you see your field as 25-AUG-15.
You can select your data without TO_DATE conversion, just matching this default format like this:
select * from table where trunc(field1)='25-AUG-15';
In fact, it's not recommended, because if someone will change the default format, Oracle will not be able to understand that you are going to tell him a DATE.
So the to_date conversion in this case:
select * from table where
trunc(field1)=to_date('25/AUG/15','DD/MON/YY');
is used to specify that you wanna tell to Oracle a DATE type with value of 25th of August 2015, using a diffrent format, specified as second parameter. (DD/MM/YY in this case).

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