Formatting DATE in oracle - oracle

I have a date field in a table that contains date in dd-MMM-yy format .
I want to create a function that get this date check it for not null and then change it to yyyy/mm/dd format
but the problem is that oracle doesn't accept dd-MMM-yy formate date as a input parameter and
it say : Please Use yyyy-MM-dd date format !!!
how can I first change dd-MMM-yy formate to yyyy-MM-dd so oracle accept it as input then change it to yyyy/mm/dd

: Please Use yyyy-MM-dd date format !!!
That is no way related to an Oracle error.
I have a date field in a table that contains date in dd-MMM-yy format .
No, you are confused. Oracle does not store dates in the format you see. It stores it internally in 7 bytes with each byte storing different components of the datetime value.
Byte Description
---- -------------------------------------------------
1 Century value but before storing it add 100 to it
2 Year and 100 is added to it before storing
3 Month
4 Day of the month
5 Hours but add 1 before storing it
6 Minutes but add 1 before storing it
7 Seconds but add 1 before storing it
If you want to display, use TO_CHAR with proper FORMAT MODEL.
While inserting, use TO_DATE with proper FORMAT MODEL.
What you see as a format by default, is your locale specific NLS settings.
SQL> select parameter, value from v$nls_parameters where parameter='NLS_DATE_FORMAT';
PARAMETER VALUE
--------------- ----------------------------------------------------------------
NLS_DATE_FORMAT DD-MON-RR
SQL> select sysdate from dual;
SYSDATE
---------
03-FEB-15
SQL> select to_char(sysdate, 'mm/dd/yyyy hh24:mi:ss') from dual;
TO_CHAR(SYSDATE,'MM
-------------------
02/03/2015 17:59:42
SQL>
Update Regarding MMM format.
By MMM if you mean the month name up to three characters, then use MON.

Related

Why is DATE data type treated like TIMESTAMP(0) data type in Oracle mode in H2?

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.

Oracle SQL/PL - ORA-01843: not a valid month

I get the error message: ORA-01843: not a valid month after executing a sql plus script.
I try using the "standard" date format yyyy-mm-dd.
Is SQL/PL not understanding the alter session statement?
set linesize 200
set pagesize 1000
alter session set NLS_NUMERIC_CHARACTERS = ',.';
alter session set NLS_DATE_FORMAT = 'yyyy-mm-dd';
select
*
from my_table
where
date >= '2019-08-31';
exit
What you do need - from my point of view - is not to compare date values to strings.
Presuming that date here actually represent a DATE datatype column (why didn't you post table description?) (as already commented, you can't name a column that way, not unless you enclosed its name into double quotes), then
where date >= '2019-08-31'
---- ------------
DATE this is a string
datatype
Use date literal, which always has a DATE keyword and date in format 'yyyy-mm-dd':
where date >= date '2019-08-31'
Or, use to_date function with appropriate format mask:
where date >= to_date('2019-08-31', 'yyyy-mm-dd')
If date column (wrong name, as we already know) actually contains strings and you hope all of them are following the 'yyyy-mm-dd' format, well, some values don't. Storing dates into varchar2 datatype column is almost always a bad idea. Nobody prevents you from storing e.g. '2019-ac-31' into it, and that isn't a valid date value.

Fetch Hours from Created date

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.

Get current timestamp in specific format with seconds to one decimal place

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.

how to insert current date into a DATE field in dd/mm/yyyy format in oracle

I have a field in my table with datatype as DATE in Oracle.
I want to insert the current date into that field, in format DD/MM/YYYY format.
I tried the below query:
select to_date(to_char(sysdate,'dd/mm/yyyy'),'dd/mm/yyyy') from dual
But it gives
1/8/2011 12:00:00 AM.
I want it to insert and show as
08/01/2011 12:00:00 AM.
Can anyone help me in this please ?
DATE is a built-in type in Oracle, which is represented in a fixed way and you have no control over it.
So:
I want it to insert [...] as 08/01/2011 12:00:00 AM
The above is nonsensical. You don't insert a string, you insert a date.
Format is useful only when you want:
to convert a string to an internal representation of date with TO_DATE (format mask: how to parse the string);
to convert an internal representation of date to a string with TO_CHAR (format mask: how to render the date).
So basically, in your example you take a DATE, you convert it to a STRING with some format, and convert it back to DATE with the same format. This is a no-op.
Now, what your client displays: this is because your Oracle Client won't display DATE fields directly and the NLS layer will convert any DATE field that is selected. So it depends on your locale by default.
What you want is SELECT TO_CHAR(SYSDATE,'DD/MM/YYYY') FROM dual; which will explicitly perform the conversion and return a string.
And when you want to insert a date in a database, you can use TO_DATE or date literals.
Alternatively, if you want to retrieve the date part of the DATE field, you may use truncate, i.e.
select to_char(trunc(sysdate),'dd/mm/yyyy') from dual;
When the column is of type DATE, you can use something like:
Insert into your_table(your_date_column) Select TRUNC(SYSDATE) from DUAL;
This removes the time part from SYSDATE.
Maybe this can help
insert into pasok values ('&kode_pasok','&kode_barang','&kode_suplier',
to_date('&tanggal_pasok','dd-mm-yyyy'),&jumlah_pasok);
note: '&' help we to insert data again, insert / end than enter to
insert again example: Enter value for kode_pembelian: BEL-E005 Enter
value for kode_barang: ELK-02 Enter value for kode_customer: B-0001
old 2: '&kode_pembelian','&kode_barang','&kode_customer', new 2:
'BEL-E005','ELK-02','B-0001', Enter value for tanggal_pembelian:
24-06-2002 Enter value for jumlah_pembelian: 2 old 3:
to_date('&tanggal_pembelian','dd-mm-yyyy'),&jumlah_pembelian) new 3:
to_date('24-06-2002','dd-mm-yyyy'),2)
1 row created.
SQL> / (enter)

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