How to convert the difference of 2 dates with a timestamp to date with timestamp again, Oracle giving number but i want to compare timestamp.
select emp_date>to_date(sysdate,'yyyy-MM-dd HH24:MI:SS')-todate('2021-03-22 10:20:12') from emp;
above query giving error: expected date but got NUMBER.
Thanks in advance
What you are saying makes no sense. Difference of two DATE datatype values is number of days between them. For example
SQL> select sysdate - to_date('21.03.2021 13:12', 'dd.mm.yyyy hh24:mi') diff from dual;
DIFF
----------
,943217593
SQL>
You CAN convert it to a prettier format (days, hours, minutes, seconds), but it is still a NUMBER, it is not a date.
Therefore, you can't compare EMP_DATE (which is a DATE datatype column, isn't it?) to a number as it just doesn't make sense.
Is 22nd of March 2021 larger or smaller than 0.94? It's neither.
[TL;DR] You cannot as your data types do not match and it does not make sense to compare a date/time value to an interval.
If you do:
date_value1 - date_value2
You will get a NUMBER data type representing the number of (fractional) days between the two date values.
You can explicitly cast the subtraction operation to get an INTERVAL DAY TO SECOND data type using:
(date_value1 - date_value2) DAY TO SECOND
So, for your code that would be:
SELECT emp_date > ( sysdate - TO_DATE( '2021-03-22 10:20:12', 'YYYY-MM-DD HH24:MI:SS' ) ) DAY TO SECOND
FROM emp;
However, that will fail as you cannot compare a DATE to an INTERVAL DAY TO SECOND and SQL does not have a boolean data type so > does not make sense.
To fix that later point you could use a CASE expression but the difference in data types is a show-stopper as you can't compare a date to an interval.
but i want to compare timestamp.
You don't have a TIMESTAMP data type, you have either a number (representing an interval in days) or an INTERVAL data type. If you want to convert it back to a DATE or TIMESTAMP then you need to add your interval to an epoch value.
Related
TRANSACTION_DATE is a DATE data type.
This code lists all of the event dates to the MI:SSSS.
select to_char(transaction_date,'YYYY-MON-DD HH24:MI:SSSS') as trans_date from ticket_orders;
Now I want to get counts for those dates and I get ORA-00979 not a GROUP BY function.
select to_char(transaction_date,'YYYY-MON-DD HH24:MI:SSSS') as trans_date,
count(*)
from ticket_orders
group by to_char(transaction_date,'YYYY-MON-DD HH24:MI:SSSS');
ERROR ORA-00979: not a GROUP BY expression
How do I get a count of transactions to the MI:SSSS precision?
A DATE data type is a binary data type that is composed of 7 bytes representing century, year-of-century, month, day, hour, minute and second. It ALWAYS has those components and it NEVER contains fractional seconds (that is for the TIMESTAMP data type which can have fractional seconds and/or time zone information).
If DATE type does not store fractional seconds, why does a typical row from my first query look like this 2021-FEB-25 07:58:2626
That is because you are displaying the seconds twice as you use the SS format model for seconds twice.
Your query can just be:
select to_char(transaction_date,'YYYY-MON-DD HH24:MI:SS') as trans_date,
count(*)
from ticket_orders
group by
transaction_date;
db<>fiddle here
The DATE data type does not store fractional seconds. You can reference the Oracle documentation about data types.
DATE
Valid date range from January 1, 4712 BC, to December 31, 9999 AD. The
default format is determined explicitly by the NLS_DATE_FORMAT
parameter or implicitly by the NLS_TERRITORY parameter. The size is
fixed at 7 bytes. This data type contains the datetime fields YEAR,
MONTH, DAY, HOUR, MINUTE, and SECOND. It does not have fractional
seconds or a time zone.
If you want a data type that stores fractional seconds you will need to use TIMESTAMP
TIMESTAMP [(fractional_seconds_precision)]
Year, month, and day values of date, as well as hour, minute, and
second values of time, where fractional_seconds_precision is the
number of digits in the fractional part of the SECOND datetime field.
Accepted values of fractional_seconds_precision are 0 to 9. The
default is 6. The default format is determined explicitly by the
NLS_TIMESTAMP_FORMAT parameter or implicitly by the NLS_TERRITORY
parameter. The size is 7 or 11 bytes, depending on the precision. This
data type contains the datetime fields YEAR, MONTH, DAY, HOUR, MINUTE,
and SECOND. It contains fractional seconds but does not have a time
zone.
Want to split DB2 date having format 2018-04-12-14.02.16.058110 to Oracle in two different columns with format YYYYMMDD and other with HHMM.
You can't do that. Oracle DATE datatype contains both DATE and TIME components, so - although you might try with different TO_CHAR (or, worse, TO_DATE or TO_TIMESTAMP) functions you find on the Internet, the final result will be the same: values will have both date & time.
Therefore, I'd suggest you to do exactly that: store YYYYMMDD HHMI (note MI - minutes, not MM - month).
For example:
SQL> select
2 cast(to_timestamp('2018-04-12-14.02.16.058110',
3 'yyyy-mm-dd-hh24.mi.ss,ff6') as date) result
4 from dual;
RESULT
-------------------
12.04.2018 14:02:16
SQL>
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/
for example
select to_timestamp(sysdate) from dual
return date object, not timestamp.
I try to change
NLS_TIMESTAMP_FORMAT='ss.ff'
but select return error.
If you are starting with sysdate then as #a_horse_with_no_name says you don't need to do a conversrion; use systimestamp or current_timestamp instead. (One is the server time, one is the client time, which will be the same unless your client is in a different timezone).
More generally though you can cast between data types:
select cast(date_field as timestamp) from your_table
You won't add any precision to the value though; the date already have a time down to second precision, even if that is midnight; and your timestamp will still have the fractional seconds part as zero.
If you just want to display your DATE as a string but show the time it already has then you need to specify the output format, e.g.
select to_char(sysdate, 'YYYY-MM-DD HH24:MI:SS') from dual
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.