I have a column in my table which will store the time as hh24miss format, i.e it stores as 091315 which is 09 hrs 13 min 15 sec. I need to convert it into HH24:MI:SS AND concatenate it with the date column which is in YYYYMMDD format.
Simply, the following columns Date: 19940601 and Time: 091315 need to be converted to
01-Jan-94 09:13:15.
You should not store dates as strings, and there is no need to store the time in a separate field. Oracle's DATE data type includes times down the to the second. (You'd need TIMESTAMP for fractions of a second).
If you are really stuck with this schema then you need to convert the two strings into a DATE:
to_date(date_column || time_column, 'YYYYMMDDHH24MISS')
You can then display that in whatever format you want; what you showed would be:
to_char(to_date(date_column || time_column, 'YYYYMMDDHH24MISS'),
'DD-Mon-RR HH24:MI:SS')
Although the data you have is June, not January.
SQL Fiddle demo.
But really, please revisit your schema and use the appropriate data type for this, don't store the values as strings. You have no validation and no easy way to check that the values you have stored actually represent valid dates and times.
Related
I'm trying to store date type data from Oracle FORMS with format mask as like DD-MM-YYYY but every time it store as like DD/MON/YY.
I already alter session with NLS_DATE_FORMAT, but result is as same as before.
Oracle internal date format that is written in the table is something you can't change in any way, but, in the same time, it is irrelevant. If you are dealing with DATE type column then you should know that it containes both the date and the time. How, where and when you will show it or use it is on you. Here is a sample of a few formats derived from that original Oracle DATE format...
WITH
t AS
(
Select SYSDATE "MY_DATE_COLUMN" From Dual
)
Select
MY_DATE_COLUMN "DATE_DEFAULT_FORMAT",
To_Char(MY_DATE_COLUMN, 'mm-dd-yyyy') "DATE_1",
To_Char(MY_DATE_COLUMN, 'yyyy/mm/dd') "DATE_2",
To_Char(MY_DATE_COLUMN, 'dd.mm.yyyy') "DATE_3",
To_Char(MY_DATE_COLUMN, 'dd.mm.yyyy hh24:mi:ss') "DATE_4"
From t
DATE_DEFAULT_FORMAT
DATE_1
DATE_2
DATE_3
DATE_4
22-OCT-22
10-22-2022
2022/10/22
22.10.2022
22.10.2022 10:59:44
You can find a lot more about the theme at https://www.oracletutorial.com/oracle-basics/oracle-date/
Regards...
In Oracle, a DATE is a binary data-type consisting of 7-bytes (representing century, year-of-century, month, day, hour, minute and second). It ALWAYS has those 7 components and it is NEVER stored in any particular human-readable format.
every time it store as like DD/MON/YY.
As already mentioned, no, it does not store a date like that; the database stores dates as 7 bytes.
What you are seeing is that the client application, that you are using to connect to the database, is receiving the 7-byte binary date value and is choosing to convert it to something that is more easily comprehensible to you, the user, and is defaulting to converting the date to a string with the format DD/MON/RR.
What you should be doing is changing how the dates are displayed by the client application by either:
Change the settings in the Toad (View > Toad Options > Data Grids > Data and set the Date Format option) and allow Toad to implicitly format the string; or
Use TO_CHAR to explicitly format the date (TO_CHAR(column_name, 'DD-MM-YYYY')).
I'm trying to store data as like DD-MM-YYYY.
If you want to store a date then STORE it as a date (which has no format) and format it when you DISPLAY it.
If you have a valid business case to store it with a format then you will need to store it as a string, rather than as a date, because you can format strings; however, this is generally considered bad practice and should be avoided.
Sadman, to add to what others have posted I suggest you do not write your applications with reliance on the NLS_DATE_FORMAT parameter but rather you screens and application should specify the expected DATE entry format and the code should use the TO_DATE function to store the data into the database. All application SQL should use the TO_CHAR function to format date output for display.
I have a table (my table ) with a varchar2 column (my_column) , this column inculdes data that may be dates, in almost every known date format. like
dd/mm/yyyy
mm/dd/yyyy
ddMONyyyy
ddmmyyyyy
yymmdd
mm.dd.yy
dd/mm/yyyy hh:24:ss
mm-dd-yyyy
and so many .
Also it could contains a free text data that may be numbers or text.
I need the possible fastest way to retrieve it as a date , and if it's cannot match any date format to retrieve null
Said that this is really a bad and dangerous way to store dates, you could try with something like the following:
select myColumn,
coalesce(
to_date(myColumn default null on conversion error, 'dd/mm/yyyy' ),
to_date(myColumn default null on conversion error, 'yyyy mm dd' ),
... /* all the known formats */
to_date(myColumn default null on conversion error ) /* dangerous */
)
from myTable
Here I would list all the possiblly expected formats, in the right order and trying to avoid the to_date without format mask, which can be really dangerous and give you unexpected results.
The simple answer is: You cannot convert the strings to dates.
You say that possible formats include 'dd/mm/yyyy' and 'mm/dd/yyyy'. So what date would '01/02/2000' be? February 1 or January 2? You cannot know this, so a conversion is impossible.
Having said that, you may want to write a stored procedure where you parse the text yourself and only convert unambiguous strings.
E.g.: Is there a substring containing colons? Then this may be the time part. In the rest of the string: Is there a four-digit number? Then this may be the year. And so on until you are either 100% sure what date/time this is or you cannot unambiguously determine the date (in which case you want to return null).
Example: '13/01/21' looks very much like January 13, 2021. Or do you allow the year 2013 in your table or even 2001 or even 1921 or ...? If you know there can be no year less then, say, 2019 in the table and no year greater than 2021, then the year must be 2021. 13 cannot be the month, so it must be the day, which leaves 01 for the month. If you cannot rule out all other options, then you would have to return null.
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.
I am at a loss as how to insert the current time in a different format than the default. Can somebody help explain?
Here is how my table was created:
CREATE TABLE ACTIVITY_LOG
(
TIME TIMESTAMP NOT NULL
, ACTIVITY VARCHAR2(200) NOT NULL
);
My insert command works:
insert into activity_log
values (localtimestamp,'blah');
But how do i insert the localtimestamp value into my table in a different format using the various MM DD YY HH MM SS tags? I've tried the following, but it gives me the ORA-1830: date format picture ends before converting entire input string error.
insert into activity_log
values (to_timestamp(localtimestamp,'YYYY/MM/DD'),'blah');
You don't insert a timestamp in a particular format. Timestamps (and dates) are stored in the database using an internal representation, which is betwen 7 and 11 bytes depending on the type and precision. There is more about that in this question, among others.
Your client or application decides how to display the value in a human-readable string form.
When you do:
to_timestamp(localtimestamp,'YYYY/MM/DD')
you are implicitly converting the localtimestamp to a string, using your session's NLS settings, and then converting it back to a timestamp. That may incidentally change the value - losing precision - but won't change how the value is stored internally. In your case the mismatch between the NLS setting and the format you are supplying is leading to an ORA-01830 error.
So your first insert is correct (assuming you really want the session time, not the server time). If you want to see the stored values in a particular format then either change your client session's NLS settings, or preferably format it explicitly when you query it, e.g.:
select to_char(time, 'YYYY-MM-DD HH24:MI:SS.FF3') from activity_log
You don't seem to provide any indication of what your 'localtimestamp' is - is that pseudocode? A variable name? A column you haven't shown the definition for?
What data type is 'localtimestamp'? What data does it contain? Pertinent questions as other answers point out, because if it truly is a time stamp then oracle will be converting it to a string for you, before passing that string to to_timestamp() in your final query. Your initial stab at it should just work if the variable is a timestamp, containing a timestamp
Ultimately "date format picture ends" means "you passed me a string looking like '2017-05-17 12:45:59', but claimed it was only 'yyyy-mm-dd'. What was I expected to do with the rest of it?"
Your current final comment on your question "I was hoping to look in the table and see a useful looking time" - that's your query tool's problem. Have a look in the setting of your query tool and change the date format it displays. As has been noted, dates in oracle are stored as a decimal number days since a certain moment in time. If 0 represents 01 Jan 1970, then 1.75 represents 6pm on the 2 Jan 1970. It is up to the end program the user is using, to format the date into something you like.. you cannot "insert a timestamp with a different format" because time stamps don't have a format any more than a number like 1.75 has a format. It is what your query does with it when it gets it out, that gives it the format:
To_char(timestampcol, 'yyyy mm did')
To-char(tomestampcol, 'mon dd yyyy')
These use oracles built in date formatter, that turns that decimal number of the date into a string in the given format; you will see a string.. or you can just write "select * from table" and run it in TOAD and toad will show you the dates according to the format in settings, or you can write a c# program and get a load of date objects out and call my date.ToString("yyyy-MM-dd") on them to format them. The idea I'm trying to get across is that you don't pick the date format on the way in, you pick it on the way out, if you don't like what you're looking at, you have to change it on the way out, not the way in
I have created a table in Oracle in which I have KPI_START_DATE column which is a Date datatype, and KPI_START_TIME which is a TIMESTAMP datatype.
Now I want to modify this date dataype for
KPI_START_DATE to dd/mm/yyyy
and
KPI_START_TIME to HH:MI:SS.
So that user should always enter the date and time in this column in this proper format.
I tried below query but its was giving error:
Alter table KPI_DEFINITION MODIFY(to_char(KPI_START_DATE,'dd/mm/yyyy') )
DATE and TIMESTAMP columns do not have any inherent readable format. The values are stored in Oracle's own internal representation, which has no resemblance to a human-readable date or time. At the point to retrieve or display a value you can convert it to whatever format you want, with to_char().
Both DATE and TIMESTAMP have date and time components (to second precision with DATE, and with fractional seconds with TIMESTAMP; plus time zone information with the extended data types), and you should not try to store them separately as two columns. Have a single column and extract the information you need at any time; to get the information out of a single column but split into two fields you could do:
select to_char(KPI_START, 'dd/mm/yyyy') as KPI_START_DATE,
to_char(KPI_START, 'hh24:mi:ss') as KPI_START_TIME
but you'd generally want both together anyway:
select to_char(KPI_START, 'dd/mm/yyyy hh24:mi:ss')
Also notice the 'hh24' format model to get the 24-hour clock time; otherwise you wouldn't see any difference between 3 a.m. and 3 p.m.
You can store a value in either type of column with the time set to midnight, but it does still have a time component - it is just midnight. You can't store a value in either type of column with just a time component - it has to have a date too. You could make that a nominal date and just ignore it, but I've never seen a valid reason to do that - you're wasting storage in two columns, and making searching for and comparing values much harder. Oracle even provides a default date if you don't specify one (first day of current month). But the value always has both a date and a time part:
create table KPI_DEFINITION (KPI_START date);
insert into KPI_DEFINITION (KPI_START)
values (to_date('27/01/2015', 'DD/MM/YYYY'));
insert into KPI_DEFINITION (KPI_START)
values (to_date('12:41:57', 'HH24:MI:SS'));
select to_char(KPI_START, 'YYYY-MM-DD HH24:MI:SS') from KPI_DEFINITION;
TO_CHAR(KPI_START,'YYYY-MM-DDHH24:MI:SS')
-----------------------------------------
2015-01-27 00:00:00
2015-01-01 12:41:57
Your users should be inserting a single value with both date and time as one:
insert into KPI_DEFINITION (KPI_START)
values (to_date('27/01/2015 12:41:57', 'DD/MM/YYYY HH24:MI:SS'));
select to_char(KPI_START, 'YYYY-MM-DD HH24:MI:SS') from KPI_DEFINITION;
TO_CHAR(KPI_START,'YYYY-MM-DDHH24:MI:SS')
-----------------------------------------
2015-01-27 12:41:57
You can also use date or timestamp literals, and if using to_date() you should always specify the full format - don't rely on NLS settings as they may be different for other users.
You should understand difference between datatype and format. DATE is a datatype. TIMESTAMP is a datatype. None of them have formats, they're just numbers.
When converting character datatype to or from date datatype, format should be applied. It's an attribute of an actual conversion, nothing else.
Look at this:
SQL> create table tmp$date(d date);
Table created
SQL> insert into tmp$date values (DATE '2010-11-01');
1 row inserted
SQL> insert into tmp$date values (DATE '2014-12-28');
1 row inserted
SQL> select d, dump(d) from tmp$date;
D DUMP(D)
----------- ---------------------------------
01.11.2010 Typ=12 Len=7: 120,110,11,1,1,1,1
28.12.2014 Typ=12 Len=7: 120,114,12,28,1,1,1
There is no any 'format' here.
DISPLAYING and STORING are NOT the same when it comes to DATE.
When people say Oracle isn’t storing the date in the format they wanted, what is really happening is Oracle is not presenting the date in the character string format they expected or wanted.
When a data element of type DATE is selected, it must be converted from its internal, binary format, to a string of characters for human consumption. The conversion of data from one type to another is known as known a “conversion”, “type casting” or “coercion”. In Oracle the conversion between dates and character strings is controlled by the NLS_DATE_FORMAT model. The NLS_DATE_FORMAT can be set in any of several different locations, each with its own scope of influence.
I could go on with my leacture over DATE data type, but I am glad that someone has already got a good writeup over this. Please read this https://edstevensdba.wordpress.com/2011/04/07/nls_date_format/