I am using Oracle10g database in which a table contains a Column with Date DataType. I am using the following query to get the record:
select to_char(START_TIME, 'YYMMDD HH24:MI:SS') from table;
So from above query, the result will be of type VARCHAR. I have tried to_Date() method but resulted in displaying only DATE. Can i convert VARCHAR to DATETIME format? The result should be of type DATETIME. Please help me how to resolve this problem.
an Oracle date contains both date and time so you can consider it a datetime (there is no datatype of datetime in Oracle). how is DISPLAYS when you select it is entirely up to your client. the default display setting is controlled by the NLS_DATE_FORMAT parameter. If you're just using the date in your pl/sql block then just assign it into a date datatype and select into that variable without to_char and it will work just fine and contain whatever time component is present in your table.
to control the display, for example using nls_date_format:
SQL> select a from datetest;
A
---------
19-FEB-13
SQL> alter session set nls_date_format='YYMMDD HH24:MI:SS';
Session altered.
SQL> select a from datetest;
A
---------------
130219 07:59:38
but again, this is only for display.
Oracle's Date type fields contain date/time values, therefore converting it to Datetime does not make any sense (it's already datetime)
Read more about oracle date types here
Yeah the Date datatype will meet your needs but you will have to jump through some hoops every time to get the exact time out of it. Definitely use the Timestamp datatype.
Related
I have an Oracle database and I have to load dat from this database to Azure SQL DWH. This is done once every day. At the beginning of the pipeline I first do a lookup on SQL DWH to look for the latest date. The result for that is something like '2015-10-25'.
I want to use this date to query the Oracle database. But I allready found out, by trying the query on Oracle that the following code does not work:
Select * from Table 1 where day = '2015-10-25'
The date in the day column looks like 25-OCT-15 (DD-MON-YY).
I treid the following where clause:
where day = TO_DATE('2015-10-25','DD-MON-YY')
But then I get the error: "literal does not match format string"
I realy don't know how to make Oracle understand this T-SQL date format.
Your Oracle column is of date datatype. When you connect to an Oracle database and write a query against that date column, you will see its default format DD-MON-YY as per this reference.
You can override this setting by running an ALTER SESSION command, eg
ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY MM DD';
but this is just in that local session. The data is still stored in Oracle in the same manner and it's simply the way you view it that is changing.
In Azure Data Factory (ADF v2) and your example, you are dealing with strings. So you must make sure any parameters you pass in are in the correct format or set to the correct datatype. The Oracle function TO_DATE converts strings to the date datatype. Therefore when passing in a string of format YYYY-MM-DD then that is the format you must use, to let the TO_DATE function know what you are passing in:
TO_DATE('2015-10-25','YYYY-MM-DD')
The function then successfully converts your parameter to a date datetype for correct comparison against the main date column.
You can try this query:
Select * from Table 1 where day = to_char (to_date('2015-10-25','YYYY-MM-DD'), 'DD-Mon-YY')
Reference this blog: how to convert YYYYMMDD to DD-Mon-YYYY in oracle?
Hope this helps.
I am trying to insert nvarchar2 values into my oracle Date field. When my source nvarchar2 value is '20701130', I want to save it as '30/11/2070' in my oracle column. And, if the source value is '21150529', I want to save it as '29/05/2115'.
I tried different formatting options to achieve this, but the year is always getting saved as two digits and is not indicating the correct century.
One of my Queries:
INSERT INTO MY_TABLE (MY_DATE_FIELD)
VALUES(TO_DATE('21061030', 'RRRR-MM-DD'));
Now, when I select after the above query, I get the result as 30/10/06 which is not we want, it should be '30/10/2106'.
You can go about it in many ways:
You alter the session date format itself to a format you want to achieve like :
ALTER SESSION SET NLS_DATE_FORMAT = 'RRRR-MM-DD';
Another approach is once you have achieved a date from a string passed using to_date then you can again add to_char to display the date in a format you want.
To_date will convert your string to a date using the format you have provided but while selecting it will still display the date as per the format provided in the session that's why we use To_char to change it to a format we want to display it into.
select to_char(TO_DATE('21061030', 'RRRR-MM-DD'),'RRRR-MM-DD') "DATE" from dual;
Thanks for the help.
I have pasted my SQL below if anyone is interested.
-- To insert into table
UPDATE MY_TABLE SET MY_DATE_FLD = TO_CHAR(TO_DATE('21061030', 'RRRR-MM-DD'),'DD-MM-YYYY') ;
-- To read from the table, this gave me the result 30/01/2106
select TO_CHAR(DATE_FLD,'DD/MM/YYY') AS START_DATE from MY_TABLE;
Appreciate the help.
Kiran.
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/
When importing columns of type "Timestamp" to an Oracle DB:
Import tbl:
02.09.13 00:00:00
After importing:
Oracle tbl:
02.09.13 08:23:44,000000000
In the Oracle tbl the type is also "Timestamp".
How can I remove the ",000000000"?
The TIMESTAMP datatype includes fractional seconds; there is no way to remove them within the database whilst maintaining the datatype. If you don't want fractional seconds then put the date into a DATE column.
It shouldn't matter whether the fractional seconds are stored or not. When selecting from the database into anything other than another date datatype you should format the date as required by the client displaying it. The normal method of doing this would be by using the function TO_CHAR(); for instance:
select to_char(column_name, 'dd.mm.yy hh24:mi:ss') from table_name
You can also do this at a session level by changing your NLS settings.
Unrelated to your question, but to address the comment on a comma being part of your timestamp; the default date format is determined by NLS_TERRITORY. A comma is a perfectly valid character to have here. Altering the NLS_TERRITORY, for example to France, it will appear as part of the NLS_DATE_FORMAT:
SQL> alter session set nls_territory = 'FRANCE';
Session altered.
SQL> select systimestamp from dual
2 ;
SYSTIMESTAMP
------------------------------------------------------------
18/09/13 13:09:54,418387 +01:00
In Oracle BI Publisher, I can't seem to find in what format the date parameters are passed in to the query. For example
select * from myTable where the_date = :the_date
Any ideas?
This would typically be via the NLS_DATE_FORMAT parameter, either set in your session or for the whole database. The default in oracle is 'DD-MON-YY'. Of course you may change your query to take it in any format you wish with the to_date conversion function.