Sum of INTERVAL DAY in Oracle [duplicate] - oracle

I am trying to sum INTERVAL. E.g.
SELECT SUM(TIMESTAMP1 - TIMESTAMP2) FROM DUAL
Is it possible to write a query that would work both on Oracle and SQL Server? If so, how?
Edit: changed DATE to INTERVAL

I'm afraid you're going to be out of luck with a solution which works in both Oracle and MSSQL. Date arithmetic is something which is very different on the various flavours of DBMS.
Anyway, in Oracle we can use dates in straightforward arithmetic. And we have a function NUMTODSINTERVAL which turns a number into a DAY TO SECOND INTERVAL. So let's put them together.
Simple test data, two rows with pairs of dates rough twelve hours apart:
SQL> alter session set nls_date_format = 'dd-mon-yyyy hh24:mi:ss'
2 /
Session altered.
SQL> select * from t42
2 /
D1 D2
-------------------- --------------------
27-jul-2010 12:10:26 27-jul-2010 00:00:00
28-jul-2010 12:10:39 28-jul-2010 00:00:00
SQL>
Simple SQL query to find the sum of elapsed time:
SQL> select numtodsinterval(sum(d1-d2), 'DAY')
2 from t42
3 /
NUMTODSINTERVAL(SUM(D1-D2),'DAY')
-----------------------------------------------------
+000000001 00:21:04.999999999
SQL>
Just over a day, which is what we would expect.
"Edit: changed DATE to INTERVAL"
Working with TIMESTAMP columns is a little more labourious, but we can still work the same trick.
In the following sample. T42T is the same as T42 only the columns have TIMESTAMP rather than DATE for their datatype. The query extracts the various components of the DS INTERVAL and converts them into seconds, which are then summed and converted back into an INTERVAL:
SQL> select numtodsinterval(
2 sum(
3 extract (day from (t1-t2)) * 86400
4 + extract (hour from (t1-t2)) * 3600
5 + extract (minute from (t1-t2)) * 600
6 + extract (second from (t1-t2))
7 ), 'SECOND')
8 from t42t
9 /
NUMTODSINTERVAL(SUM(EXTRACT(DAYFROM(T1-T2))*86400+EXTRACT(HOURFROM(T1-T2))*
---------------------------------------------------------------------------
+000000001 03:21:05.000000000
SQL>
At least this result is in round seconds!

Ok, after a bit of hell, with the help of the stackoverflowers' answers I've found the solution that fits my needs.
SELECT
SUM(CAST((DATE1 + 0) - (DATE2 + 0) AS FLOAT) AS SUM_TURNAROUND
FROM MY_BEAUTIFUL_TABLE
GROUP BY YOUR_CHOSEN_COLUMN
This returns a float (which is totally fine for me) that represents days both on Oracle ant SQL Server.
The reason I added zero to both DATEs is because in my case date columns on Oracle DB are of TIMESTAMP type and on SQL Server are of DATETIME type (which is obviously weird). So adding zero to TIMESTAMP on Oracle works just like casting to date and it does not have any effect on SQL Server DATETIME type.
Thank you guys! You were really helpful.

You can't sum two datetimes. It wouldn't make sense - i.e. what does 15:00:00 plus 23:59:00 equal? Some time the next day? etc
But you can add a time increment by using a function like Dateadd() in SQL Server.

In SQL Server as long as your individual timespans are all less than 24 hours you can do something like
WITH TIMES AS
(
SELECT CAST('01:01:00' AS DATETIME) AS TimeSpan
UNION ALL
SELECT '00:02:00'
UNION ALL
SELECT '23:02:00'
UNION ALL
SELECT '17:02:00'
--UNION ALL SELECT '24:02:00' /*This line would fail!*/
),
SummedTimes As
(
SELECT cast(SUM(CAST(TimeSpan AS FLOAT)) as datetime) AS [Summed] FROM TIMES
)
SELECT
FLOOR(CAST(Summed AS FLOAT)) AS D,
DATEPART(HOUR,[Summed]) AS H,
DATEPART(MINUTE,[Summed]) AS M,
DATEPART(SECOND,[Summed]) AS S
FROM SummedTimes
Gives
D H M S
----------- ----------- ----------- -----------
1 17 7 0
If you wanted to handle timespans greater than 24 hours I think you'd need to look at CLR integration and the TimeSpan structure. Definitely not portable!
Edit: SQL Server 2008 has a DateTimeOffset datatype that might help but that doesn't allow either SUMming or being cast to float

I also do not think this is possible. Go with custom solutions that calculates the date value according to your preferences.

You can also use this:
select
EXTRACT (DAY FROM call_end_Date - call_start_Date)*86400 +
EXTRACT (HOUR FROM call_end_Date - call_start_Date)*3600 +
EXTRACT (MINUTE FROM call_end_Date - call_start_Date)*60 +
extract (second FROM call_end_Date - call_start_Date) as interval
from table;

You Can write you own aggregate function :-). Please read carefully http://docs.oracle.com/cd/B19306_01/appdev.102/b14289/dciaggfns.htm
You must create object type and its body by template, and next aggregate function what using this object:
create or replace type Sum_Interval_Obj as object
(
-- Object for creating and support custom aggregate function
duration interval day to second, -- In this property You sum all interval
-- Object Init
static function ODCIAggregateInitialize(
actx IN OUT Sum_Interval_Obj
) return number,
-- Iterate getting values from dataset
member function ODCIAggregateIterate(
self IN OUT Sum_Interval_Obj,
ad_interval IN interval day to second
) return number,
-- Merge parallel summed data
member function ODCIAggregateMerge(
self IN OUT Sum_Interval_Obj,
ctx2 IN Sum_Interval_Obj
) return number,
-- End of query, returning summary result
member function ODCIAggregateTerminate
(
self IN Sum_Interval_Obj,
returnValue OUT interval day to second,
flags IN number
) return number
)
/
create or replace type body Sum_Interval_Obj is
-- Object Init
static function ODCIAggregateInitialize(
actx IN OUT Sum_Interval_Obj
) return number
is
begin
actx := Sum_Interval_Obj(numtodsinterval(0,'SECOND'));
return ODCIConst.Success;
end ODCIAggregateInitialize;
-- Iterate getting values from dataset
member function ODCIAggregateIterate(
self IN OUT Sum_Interval_Obj,
ad_interval IN interval day to second
) return number
is
begin
self.duration := self.duration + ad_interval;
return ODCIConst.Success;
exception
when others then
return ODCIConst.Error;
end ODCIAggregateIterate;
-- Merge parallel calculated intervals
member function ODCIAggregateMerge(
self IN OUT Sum_Interval_Obj,
ctx2 IN Sum_Interval_Obj
) return number
is
begin
self.duration := self.duration + ctx2.duration; -- Add two intervals
-- return = All Ok!
return ODCIConst.Success;
exception
when others then
return ODCIConst.Error;
end ODCIAggregateMerge;
-- End of query, returning summary result
member function ODCIAggregateTerminate(
self IN Sum_Interval_Obj,
returnValue OUT interval day to second,
flags IN number
) return number
is
begin
-- return = All Ok, too!
returnValue := self.duration;
return ODCIConst.Success;
end ODCIAggregateTerminate;
end;
/
-- You own new aggregate function:
CREATE OR REPLACE FUNCTION Sum_Interval(
a_Interval interval day to second
) RETURN interval day to second
PARALLEL_ENABLE AGGREGATE USING Sum_Interval_Obj;
/
Last, check your function:
select sum_interval(duration)
from (select numtodsinterval(1,'SECOND') as duration from dual union all
select numtodsinterval(1,'MINUTE') as duration from dual union all
select numtodsinterval(1,'HOUR') as duration from dual union all
select numtodsinterval(1,'DAY') as duration from dual);
Finally You can create SUM function, if you want.

Related

Generuc function to generate date intervals

I gave the following code to several QA teams, which works fine.
with dt (dt, interv) as (
select TIMESTAMP '2022-11-01 02:37:11', numtodsinterval(5,'MINUTE') from dual
union all
select dt.dt + interv, interv from dt
where dt.dt + interv <
TIMESTAMP '2022-11-01 05:00:00')
select dt from dt;
The problem is VALUES are hardcoded and way too often when a person changes to put different values they make a mistake editing, which causes the code to fail.
Can this code be modified to a pipeline function or a procedure with an out parameter or a macro to prevent such problems.
I would need to pass in 2 dates(order of dates passed should not screw things up. Perhaps use least(), greatest()) an INTERVAL 'N' and a unit S=second M=MINUTE H=hour or D=Day.
Thanks to all who answer and your expertise.
As a macro:
CREATE OR REPLACE FUNCTION gen_dt(i_from_dat IN TIMESTAMP, i_to_dat IN TIMESTAMP, i_interval IN NUMBER, i_interval_type IN VARCHAR2)
RETURN VARCHAR2
SQL_MACRO
IS
BEGIN
RETURN q'~SELECT LEAST(i_from_dat,i_to_dat) + NUMTODSINTERVAL( (LEVEL-1)*i_interval, i_interval_type ) AS dt
FROM DUAL
CONNECT BY LEAST(i_from_dat,i_to_dat) + NUMTODSINTERVAL( (LEVEL-1)*i_interval, i_interval_type) < GREATEST(i_from_dat, i_to_dat)~';
END ;
(Note that you can't use WITH clause because there is a bug preventing substitution of variables inside the WITH() part)
SELECT * FROM gen_dt(SYSTIMESTAMP, SYSTIMESTAMP+1, 4, 'HOUR') ;
03/11/22 13:48:23,072872000
03/11/22 17:48:23,072872000
03/11/22 21:48:23,072872000
04/11/22 01:48:23,072872000
04/11/22 05:48:23,072872000
04/11/22 09:48:23,072872000

'Different results for the same function called from SQL Developer UI and in SQL query

F is a function counting the number of weekdays betwwen two dates (using the format to_date(a, 'DD/MM/YYYY') [NLS_DATE_LANGUAGE = "FRENCH"].
It is stored in package P.
With a is the beginning date of the period and b the end.
When I use the SQL developer to run the function i.e. Right click on package p, execute, choose f function and fill the arguments:
if a = to_date('02/08/2019', 'DD/MM/YYYY') and b = to_date('12/08/2019', 'DD/MM/YYYY'))
I get a number of days = 7, which is the correct result.
But when I run it in SQL:
select p.f('02/08/2019','12/08/2019') from DUAL
I get a number of days = 8 and this result is obviously wrong.
I cannot understand how these two process can return two different values since the same F function is called, and the arguments are exactly the same.
I have been careful about the date format, still the two ways of calling f won't return the same result.
For information, this is the content of this function (sorry, cariable are expressed in french)
FUNCTION getjoursouvres
(
i_debut IN DATE,
i_fin IN DATE
)
RETURN NUMBER IS o_result NUMBER;
v_jour date;
v_nbjours NUMBER;
v_testferie number;
v_testweekend number;
v_testglobal number;
-- This cursor browses all dates between i_debut and i_fin (included)
cursor cx is
select to_date(i_debut, 'DD/MM/YYYY') + rownum -1 dt
from dual
connect by level <= to_date(i_fin, 'DD/MM/YYYY') - to_date(i_debut, 'DD/MM/YYYY') + 1;
BEGIN
open cx;
v_nbjours := 0;
loop
-- Browses all the days in the interval (begining and end included)
fetch cx into v_jour;
exit when cx%NOTFOUND;
-- testferie return 1 if the day is NOT a holiday, 0 if it is (so not be be added)
v_testferie := testferie(v_jour);
-- testweekend return 1 if the day is a weekday, 0 if it is on weekend (so not be be
v_testweekend := testweekend(v_jour);
--
v_testglobal := v_testferie + v_testweekend;
-- If v_testglobal = 2 then the day is neither weekend nor holiday. Therefore it is aded to the sum of days
if v_test = 2 then
v_nbjours := v_nbjours + 1;
end if;
end loop;
o_result := v_nbjours;
close cx;
return o_result;
END;
After many calls of both way to use the function. I reach to the conclusion that the element inducing the anomaly comes from the ue of
to_date(v_date, 'DD/MM/YYYY')
where v_date is already declared as a date format behave in an inpredictable way.
I decided to keep the date variable as such, and only use to_date for different cariable format.
I am not able to explain why exactly, but it solved my problems concerning dates behavior. Now I can call a function with data parameter from DUAL or from the SQL developer interface and get identical and coherent results.

Create View with 365 days

How to Create a View with all days in year. view should fill with dates from JAN-01 to Dec-31. How can I do this in Oracle ?
If current year have 365 days,view should have 365 rows with dates. if current year have 366 days,view should have 366 rows with dates. I want the view to have a single column of type DATE.
This simple view will do it:
create or replace view year_days as
select trunc(sysdate, 'YYYY') + (level-1) as the_day
from dual
connect by level <= to_number(to_char(last_day(add_months(trunc(sysdate, 'YYYY'),11)), 'DDD'))
/
Like this:
SQL> select * from year_days;
THE_DAY
---------
01-JAN-11
02-JAN-11
03-JAN-11
04-JAN-11
05-JAN-11
06-JAN-11
07-JAN-11
08-JAN-11
09-JAN-11
10-JAN-11
11-JAN-11
...
20-DEC-11
21-DEC-11
22-DEC-11
23-DEC-11
24-DEC-11
25-DEC-11
26-DEC-11
27-DEC-11
28-DEC-11
29-DEC-11
30-DEC-11
31-DEC-11
365 rows selected.
SQL>
The date is generated by applying several Oracle date functions:
trunc(sysdate, 'yyyy') gives us the first of January for the current year
add_months(x, 11) gives us the first of December
last_day(x) gives us the thirty-first of December
to_char(x, 'DDD') gives us the number of the thirty-first of December, 365 this year and 366 next.
This last figure provides the upper bound for the row generator CONNECT BY LEVEL <= X
you can use piplined table, it should be something like this:
create or replace type year_date_typ as object (v_day date);
create or replace type year_date_tab as table of year_date_typ;
CREATE OR REPLACE FUNCTION get_dates(year IN VARCHAR2) RETURN year_date_tab PIPELINED IS
v_start_date date := to_date('0101' || year, 'ddmmyyyy');
res year_date_typ := year_date_typ(null);
v_days_in_year integer := 365;
BEGIN
if to_char(last_day(to_date('0102'||year, 'ddmmyyyy')), 'dd') = '29' then
v_days_in_year := 366;
end if;
FOR i in 0 .. v_days_in_year integer-1 LOOP
res.v_day := v_start_date + i;
pipe row(res);
END LOOP;
return;
END get_dates;
and you can use it:
select * from table(get_dates('2011'));
This works well in MS SQL
SELECT TOP (DATEDIFF(day, DATEADD(yy, DATEDIFF(yy,0,getdate()), 0), DATEADD(yy, DATEDIFF(yy,0,getdate()) + 1, -1))) n = ROW_NUMBER() OVER (ORDER BY [object_id]),
dateadd(day, ROW_NUMBER() OVER (ORDER BY [object_id]) - 1, DATEADD(yy, DATEDIFF(yy,0,getdate()), 0)) AS AsOfDate FROM sys.all_objects

How to handle to_date exceptions in a SELECT statment to ignore those rows?

I have the following query that I am attempting to use as a COMMAND in a crystal report that I am working on.
SELECT * FROM myTable
WHERE to_date(myTable.sdate, 'MM/dd/yyyy') <= {?EndDate}
This works fine, however my only concern is that the date may not always be in the correct format (due to user error). I know that when the to_date function fails it throws an exception.. is it possible to handle this exception in such a way that it ignores the corresponding row in my SELECT statement? Because otherwise my report would break if only one date in the entire database is incorrectly formatted.
I looked to see if Oracle offers an isDate function, but it seems like you are supposed to just handle the exception. Any help would be greatly appreciated. Thanks!!
Echoing Tony's comment, you'd be far better off storing dates in DATE columns rather than forcing a front-end query tool to find and handle these exceptions.
If you're stuck with an incorrect data model, however, the simplest option in earlier versions is to create a function that does the conversion and handles the error,
CREATE OR REPLACE FUNCTION my_to_date( p_date_str IN VARCHAR2,
p_format_mask IN VARCHAR2 )
RETURN DATE
IS
l_date DATE;
BEGIN
l_date := to_date( p_date_str, p_format_mask );
RETURN l_date;
EXCEPTION
WHEN others THEN
RETURN null;
END my_to_date;
Your query would then become
SELECT *
FROM myTable
WHERE my_to_date(myTable.sdate, 'MM/dd/yyyy') <= {?EndDate}
Of course, you'd most likely want a function-based index on the MY_TO_DATE call in order to make this query reasonably efficient.
In 12.2, Oracle has added extensions to the to_date and cast functions to handle conversions that error
SELECT *
FROM myTable
WHERE to_date(myTable.sdate default null on conversion error, 'MM/dd/yyyy') <= {?EndDate}
You could also use the validate_conversion function if you're looking for all the rows that are (or are not) valid dates.
SELECT *
FROM myTable
WHERE validate_conversion( myTable.sdate as date, 'MM/DD/YYYY' ) = 1
If your data is not consistent and dates stored as strings may not be valid then you have 3 options.
Refactor your DB to make sure that the column stores a date datatype
Handle the exception of string to date in a stored procedure
Handle the exception of string to date in a (complex) record selection formula
I would suggest using the first option as your data should be consistent.
The second option will provide some flexibility and speed as the report will only fetch the rows that are needed.
The third option will force the report to fetch every record in the table and then have the report filter down the records.
I have the same problem... an old legacy database with varchar fields for dates and decades of bad data in the field. As much as I'd like to, I can't change the datatypes either. But I came up with this solution to find if a date is current, which seems to be what you're doing as well:
select * from MyTable
where regexp_like(sdate, '[0-1][0-9].[0-3][0-9].[0-9][0-9][0-9][0-9]')
-- make sure it's in the right format and ignore rows that are not
and substr(sdate,7,10) || substr(sdate,1,2) || substr(sdate,4,5) >= to_char({?EndDate}, 'YYYYMMDD')
-- put the date in ISO format and do a string compare
The benefit of this approach is it doesn't choke on dates like "February 30".
Starting from Oracle 12c there is no need to define a function to catch the conversion exception.
Oracle introduced an ON CONVERSION ERROR clause in the TO_DATE function.
Basically the clause suppress the error in converting of an invalid date string (typical errors are ORA-01843, ORA-01841, ORA-011861, ORA-01840) and returns a specified default value or null.
Example of usage
select to_date('2020-99-01','yyyy-mm-dd') from dual;
-- ORA-01843: not a valid month
select to_date('2020-99-01' default null on conversion error,'yyyy-mm-dd') from dual;
-- returns NULL
select to_date('2020-99-01' default '2020-01-01' on conversion error,'yyyy-mm-dd') from dual;
-- 01.01.2020 00:00:00
Solution for the Legacy Application
Let's assume there is a table with a date column stored as VARCHAR2(10)
select * from tab;
DATE_CHAR
----------
2021-01-01
2021-99-01
Using the above feature a VIRTUAL DATE column is defined, that either shows the DATE or NULL in case of the conversion error
alter table tab add (
date_d DATE as (to_date(date_char default null on conversion error,'yyyy-mm-dd')) VIRTUAL
);
select * from tab;
DATE_CHAR DATE_D
---------- -------------------
2021-01-01 01.01.2021 00:00:00
2021-99-01
The VIRTUAL column can be safely used because its format is DATE and if required an INDEX can be set up on it.
select * from tab where date_d = date'2021-01-01';
Since you say that you have "no access" to the database, I am assuming that you can not create any functions to help you with this and that you can only run queries?
If that is the case, then the following code should get you most of what you need with the following caveats:
1) The stored date format that you want to evaluate is 'mm/dd/yyyy'. If this is not the case, then you can alter the code to fit your format.
2) The database does not contain invalid dates such as Feb 30th.
First, I created my test table and test data:
create table test ( x number, sdate varchar2(20));
insert into test values (1, null);
insert into test values (2, '01/01/1999');
insert into test values (3, '1999/01/01');
insert into test values (4, '01-01-1999');
insert into test values (5, '01/01-1999');
insert into test values (6, '01-01/1999');
insert into test values (7, '12/31/1999');
insert into test values (8, '31/12/1999');
commit;
Now, the query:
WITH dates AS (
SELECT x
, sdate
, substr(sdate,1,2) as mm
, substr(sdate,4,2) as dd
, substr(sdate,7,4) as yyyy
FROM test
WHERE ( substr(sdate,1,2) IS NOT NAN -- make sure the first 2 characters are digits
AND to_number(substr(sdate,1,2)) between 1 and 12 -- and are between 0 and 12
AND substr(sdate,3,1) = '/' -- make sure the next character is a '/'
AND substr(sdate,4,2) IS NOT NAN -- make sure the next 2 are digits
AND to_number(substr(sdate,4,2)) between 1 and 31 -- and are between 0 and 31
AND substr(sdate,6,1) = '/' -- make sure the next character is a '/'
AND substr(sdate,7,4) IS NOT NAN -- make sure the next 4 are digits
AND to_number(substr(sdate,7,4)) between 1 and 9999 -- and are between 1 and 9999
)
)
SELECT x, sdate
FROM dates
WHERE to_date(mm||'/'||dd||'/'||yyyy,'mm/dd/yyyy') <= to_date('08/01/1999','mm/dd/yyyy');
And my results:
X SDATE
- ----------
2 01/01/1999
The WITH statement will do most of the validating to make sure that the sdate values are at least in the proper format. I had to break out each time unit month / day / year to do the to_date evaluation because I was still getting an invalid month error when I did a to_date on sdate.
I hope this helps.
Trust this reply clarifies...
there is no direct EXCEPTION HANDLER for invalid date.
One easy way is given below once you know the format like DD/MM/YYYY then below given REGEXP_LIKE function will work like a charm.
to_date() also will work, when invalid_date is found then cursor will goto OTHERS EXCEPTION. given below.
DECLARE
tmpnum NUMBER; -- (1=true; 0 = false)
ov_errmsg LONG;
tmpdate DATE;
lv_date VARCHAR2 (15);
BEGIN
lv_date := '6/2/2018'; -- this will fail in *regexp_like* itself
lv_date := '06/22/2018'; -- this will fail in *to_date* and will be caught in *exception WHEN OTHERS* block
lv_date := '07/03/2018'; -- this will succeed
BEGIN
tmpnum := REGEXP_LIKE (lv_date, '[0-9]{2}/[0-9]{2}/[0-9]{4}');
IF tmpnum = 0
THEN -- (1=true; 0 = false)
ov_errmsg := '1. INVALID DATE FORMAT ';
DBMS_OUTPUT.PUT_LINE (ov_errmsg);
RETURN;
END IF;
tmpdate := TO_DATE (lv_date, 'DD/MM/RRRR');
--tmpdate := TRUNC (NVL (to_date(lv_date,'DD/MM/RRRR'), SYSDATE));
tmpnum := 1;
EXCEPTION
WHEN OTHERS
THEN
BEGIN
tmpnum := 0;
ov_errmsg := '2. INVALID DATE FORMAT ';
DBMS_OUTPUT.PUT_LINE (ov_errmsg || SQLERRM);
RETURN;
END;
-- continue with your other query blocks
END;
-- continue with your other query blocks
DBMS_OUTPUT.PUT_LINE (tmpnum);
END;

In Oracle, is there a function that calculates the difference between two Dates?

In Oracle, is there a function that calculates the difference between two Dates? If not, is a way to display the difference between two dates in hours and minutes?
Query:
SELECT Round(max((EndDate - StartDate ) * 24), 2) as MaximumScheduleTime,
Round(min((EndDate - StartDate) * 24), 2) as MinimumScheduleTime,
Round(avg((EndDate - StartDate) * 24), 2) as AveragegScheduleTime
FROM table1
You can subtract two dates in Oracle. The result is a FLOAT which represents the number of days between the two dates. You can do simple arithmetic on the fractional part to calculate the hours, minutes and seconds.
Here's an example:
SELECT TO_DATE('2000/01/02:12:00:00PM', 'yyyy/mm/dd:hh:mi:ssam')-TO_DATE('2000/01/01:12:00:00AM', 'yyyy/mm/dd:hh:mi:ssam') DAYS FROM DUAL
Results in: 1.5
You can use these functions :
1) EXTRACT(element FROM temporal_value)
2) NUMTOYMINTERVAL (n, unit)
3) NUMTODSINTERVAL (n, unit).
For example :
SELECT EXTRACT(DAY FROM NUMTODSINTERVAL(end_time - start_time, 'DAY'))
|| ' days ' ||
EXTRACT(HOUR FROM NUMTODSINTERVAL(end_time - start_time, 'DAY'))
||':'||
EXTRACT(MINUTE FROM NUMTODSINTERVAL(end_time - start_time, 'DAY'))
||':'||
EXTRACT(SECOND FROM NUMTODSINTERVAL(end_time - start_time, 'DAY'))
"Lead Time"
FROM table;
With Oracle Dates, this is pretty
trivial, you can get either TOTAL
(days, hours, minutes, seconds)
between 2 dates simply by subtracting
them or with a little mod'ing you can
get Days/Hours/Minutes/Seconds
between.
http://asktom.oracle.com/tkyte/Misc/DateDiff.html
Also, from the above link:
If you really want 'datediff' in your
database, you can just do something
like this:
SQL> create or replace function datediff( p_what in varchar2,
2 p_d1 in date,
3 p_d2 in date ) return number
4 as
5 l_result number;
6 begin
7 select (p_d2-p_d1) *
8 decode( upper(p_what),
9 'SS', 24*60*60, 'MI', 24*60, 'HH', 24, NULL )
10 into l_result from dual;
11
11 return l_result;
12 end;
13 /
Function created
Q: In Oracle, is there a function that calculates the difference between two Dates?
Just subtract one date expression from another to get the difference expressed as a number of days. The integer portion is the number of whole days, the fractional portion is the fraction of a day. Simple arithmetic after that, multiply by 24 to get hours.
Q: If not, is a way to display the difference between two dates in hours and minutes?
It's just a matter of expressing the duration as whole hours and remainder minutes.
We can go "old school" to get durations in hhhh:mi format using a combination of simple builtin functions:
SELECT decode(sign(t.maxst),-1,'-','')||to_char(floor(abs(t.maxst)/60))||
decode(t.maxst,null,'',':')||to_char(mod(abs(t.maxst),60),'FM00')
as MaximumScheduleTime
, decode(sign(t.minst),-1,'-','')||to_char(floor(abs(t.minst)/60))||
decode(t.minst,null,'',':')||to_char(mod(abs(t.minst),60),'FM00')
as MinimumScheduleTime
, decode(sign(t.avgst),-1,'-','')||to_char(floor(abs(t.avgst)/60))
decode(t.avgst,null,'',':')||to_char(mod(abs(t.avgst),60),'FM00')
as AverageScheduleTime
FROM (
SELECT round(max((EndDate - StartDate) *1440),0) as maxst
, round(min((EndDate - StartDate) *1440),0) as minst
, round(avg((EndDate - StartDate) *1440),0) as avgst
FROM table1
) t
Yeah, it's fugly, but it's pretty fast. Here's a simpler case, that shows better what's going on:
select dur as "minutes"
, abs(dur) as "unsigned_minutes"
, floor(abs(dur)/60) as "unsigned_whole_hours"
, to_char(floor(abs(dur)/60)) as "hhhh"
, mod(abs(dur),60) as "unsigned_remainder_minutes"
, to_char(mod(abs(dur),60),'FM00') as "mi"
, decode(sign(dur),-1,'-','') as "leading_sign"
, decode(dur,null,'',':') as "colon_separator"
from (select round(( date_expr1 - date_expr2 )*24*60,0) as dur
from ...
)
(replace date_expr1 and date_expr2 with date expressions)
let's unpack this
date_expr1 - date_expr2 returns difference in number of days
multiply by 1440 (24*60) to get duration in minutes
round (or floor) to resolve fractional minutes into integer minutes
divide by 60, integer quotient is hours, remainder is minutes
abs function to get absolute value (change negative values to positive)
to_char format model FM00 give two digits (leading zeros)
use decode function to format a negative sign and a colon (if needed)
The SQL statement could be made less ugly using a PL/SQL function, one that takes two DATE arguments a duration in (fractional) days and returns formatted hhhh:mi
(untested)
create function hhhhmi(an_dur in number)
return varchar2 deterministic
is
begin
if an_dur is null then
return null;
end if;
return decode(sign(an_dur),-1,'-','')
|| to_char(floor(abs(an_dur)*24))
||':'||to_char(mod((abs(an_dur)*1440),60),'FM00');
end;
With the function defined:
SELECT hhhhmi(max(EndDate - StartDate)) as MaximumScheduleTime
, hhhhmi(min(EndDate - StartDate)) as MinimumScheduleTime
, hhhhmi(avg(EndDate - StartDate)) as AverageScheduleTime
FROM table1
You can use the months_between function to convert dates to the difference in years and then use between the decimal years you are interested:
CASE
WHEN ( ( MONTHS_BETWEEN( TO_DATE(date1, 'YYYYMMDD'),
TO_DATE(date1,'YYYYMMDD'))/12
)
BETWEEN Age1DecimalInYears AND Age2DecimalInYears
)
THEN 'It is between the two dates'
ELSE 'It is not between the two dates'
END;
You may need to change date format to match the a given date format and verify that 31 day months work for your specific scenarios.
References:
( found on www on 05/15/2015 )
1. Oracle/PLSQL: MONTHS_BETWEEN Function
2. Oracle Help Center - MONTHS_BETWEEN

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