Just the month january not working - oracle

In this query I found the weeks of month, for example november begin 1th Wednesday and ends sunday 5.
These are the first week on november.
SELECT * FROM (
WITH days AS
(SELECT to_date('01012017','ddmmyyyy') + level-1 date_in
FROM dual
CONNECT BY level < 32)
SELECT date_in,
TO_CHAR(date_in,'IW') - TO_CHAR(TRUNC(date_in,'MM'),'IW') + 1 week_number
FROM days) where week_number = 1;
The week_number can change depending of the weeks of the month, but in January is not working.

Your requirement is not clear for me but perhaps you are looking for this:
SELECT TRUNC (next_day(TRUNC(TO_DATE('20022017','ddmmyyyy'), 'mm'),'monday') - 1), 'IW') AS first_week
FROM dual;

I'm still a bit unclear as to what you're looking for, but perhaps the following query will help you on your way:
WITH YEAR_START AS (SELECT TO_DATE('01012017', 'DDMMYYYY') AS FIRST_DAY_OF_YEAR
FROM DUAL),
MONTH_START AS (SELECT FIRST_DAY_OF_YEAR AS FIRST_DAY_OF_MONTH
FROM YEAR_START
UNION ALL
SELECT ADD_MONTHS(FIRST_DAY_OF_YEAR, LEVEL) AS FIRST_DAY_OF_MONTH
FROM YEAR_START
CONNECT BY LEVEL <= 11),
MONTH_START_AND_END AS (SELECT FIRST_DAY_OF_MONTH,
ADD_MONTHS(FIRST_DAY_OF_MONTH, 1) - INTERVAL '1' DAY AS LAST_DAY_OF_MONTH
FROM MONTH_START),
ABS_MONTH_WEEKS AS (SELECT FIRST_DAY_OF_MONTH,
LAST_DAY_OF_MONTH,
TO_NUMBER(TO_CHAR(FIRST_DAY_OF_MONTH, 'IW')) AS ABS_FIRST_WEEK_OF_MONTH,
TO_NUMBER(TO_CHAR(LAST_DAY_OF_MONTH, 'IW')) AS ABS_LAST_WEEK_OF_MONTH
FROM MONTH_START_AND_END),
REL_MONTH_WEEKS AS (SELECT a.*,
1 AS REL_FIRST_WEEK_OF_MONTH,
ABS_LAST_WEEK_OF_MONTH - CASE
WHEN ABS_FIRST_WEEK_OF_MONTH > ABS_LAST_WEEK_OF_MONTH THEN 0
ELSE ABS_FIRST_WEEK_OF_MONTH-1
END AS REL_LAST_WEEK_OF_MONTH
FROM ABS_MONTH_WEEKS a)
SELECT *
FROM REL_MONTH_WEEKS;
Best of luck.

Related

Oracle: Return the specific records based on one column date

I have a database structure as below.
period
month
start_date
1
April
2022-04-01
2
May
2022-05-07
3
June
2022-06-04
4
July
2022-07-02
5
August
2022-08-06
6
September
2022-09-03
7
October
2022-10-01
8
November
2022-11-05
9
December
2022-12-03
10
January
2023-01-01
11
February
2023-02-04
12
March
2023-03-04
End date of the year is 2023-03-31.
Based on current_date, how do I select the query to return where the current date falls under Period 6.
My current query as below.
SELECT period FROM table1 as a
WHERE
a.start_date = (SELECT MAX(start_date) FROM table1 as b WHERE
b.start_date <=current_date) and ROWNUM <= 1
Is there anyway to improve the current query which to avoid using subquery?
Today is September 22nd, so - would this do?
Some sample data:
SQL> with test (period, month, start_date) as
2 (select 1, 'april' , date '2022-04-01' from dual union all
3 select 5, 'august' , date '2022-08-06' from dual union all
4 select 6, 'september', date '2022-09-03' from dual union all
5 select 7, 'october' , date '2022-10-01' from dual union all
6 select 10, 'january' , date '2023-01-01' from dual union all
7 select 12, 'march' , date '2023-03-04' from dual
8 ),
Query begins here:
9 temp as
10 (select period, month, start_date,
11 row_number() over (order by start_date desc) rn
12 from test
13 where start_date <= sysdate
14 )
15 select period
16 from temp
17 where rn = 1
18 /
PERIOD
----------
6
SQL>
It still uses a subquery (or a CTE, as in my example), but - as opposed to your approach, it selects from the source table only once, so performance should be improved.
A few more tests: instead of sysdate (line #13), presume that today is September 2nd (which means that it is in period #5):
9 temp as
10 (select period, month, start_date,
11 row_number() over (order by start_date desc) rn
12 from test
13 where start_date <= date '2022-09-02'
14 )
15 select period
16 from temp
17 where rn = 1;
PERIOD
----------
5
SQL>
Or, if today were August 7th:
9 temp as
10 (select period, month, start_date,
11 row_number() over (order by start_date desc) rn
12 from test
13 where start_date <= date '2022-08-07'
14 )
15 select period
16 from temp
17 where rn = 1;
PERIOD
----------
5
SQL>
Your rule for the start_date appears to be:
If the month is January (first month of the calendar year) or April (typically, first month of the financial year) then use the 1st of that month;
Otherwise use the 1st Saturday of the month.
If that is the case then you can calculate the start date of the next month and use the query:
SELECT *
FROM table1
WHERE start_date <= SYSDATE
AND SYSDATE < CASE
WHEN EXTRACT(MONTH FROM ADD_MONTHS(start_date, 1))
IN (1, 4) -- 1st month of calendar or financial year
THEN TRUNC(ADD_MONTHS(start_date, 1), 'MM')
ELSE NEXT_DAY(TRUNC(ADD_MONTHS(start_date, 1), 'MM') - 1, 'SATURDAY')
END
Then, for your sample data:
CREATE TABLE table1 (
period NUMBER(2,0),
month VARCHAR2(9)
GENERATED ALWAYS AS (
CAST(
TO_CHAR(start_date, 'FXMonth', 'NLS_DATE_LANGUAGE=English')
AS VARCHAR2(9)
)
),
start_date DATE
);
INSERT INTO table1 (period, start_date)
SELECT LEVEL,
CASE
WHEN EXTRACT(MONTH FROM ADD_MONTHS(DATE '2022-04-01', LEVEL - 1))
IN (1, 4) -- 1st month of calendar or financial year
THEN ADD_MONTHS(DATE '2022-04-01', LEVEL - 1)
ELSE NEXT_DAY(ADD_MONTHS(DATE '2022-04-01', LEVEL - 1) - 1, 'SATURDAY')
END
FROM DUAL
CONNECT BY LEVEL <= 12;
Outputs:
PERIOD
MONTH
START_DATE
6
September
2022-09-03 00:00:00
fiddle

How to get last workday before holiday in Oracle [duplicate]

This question already has answers here:
How to get the previous working day from Oracle?
(4 answers)
Closed 1 year ago.
need help for some oracle stuff ..
I need to get Day-1 from sysdate, holiday and weekend will be excluded .
And for holiday, we need to get the range to get the last workday before holiday.
The start date and end date will coming from my holiday table.
ex :
Holiday Table
HolidayName
Start_date
End_Date
holiday1
5th Aug'21
6th Aug'21
condition :
this query run on 9th Aug 2021
expected result :
4th Aug'21
I've tried some query and function but I just can't get what I need.
Thanks a lot for help!
Here's one way to do it.
select max(d) as last_workday
from (select trunc(sysdate)-level as d from dual connect by level < 30) prior_month
where to_char(d, 'DY') not in ('SAT','SUN')
and not exists (select holidayname from holiday_table
where prior_month.d between start_date and end_date)
;
Without seeing your Holiday table, it's hard to say how many days back you would need to look to find the last workday. If you have a holiday that lasts for more than 30 days, you'll need to change the 30 to a larger number.
You can use a simple case expression to determine what day of the week the start of your holiday is, then subtract a number of days based on that.
WITH
holiday (holidayname, start_date, end_date)
AS
(SELECT 'holiday1', DATE '2021-8-5', DATE '2021-8-6' FROM DUAL
UNION ALL
SELECT 'Christmas', DATE '2021-12-25', DATE '2021-12-26' FROM DUAL
UNION ALL
SELECT 'July 4th', DATE '2021-7-4', DATE '2021-7-5' FROM DUAL)
SELECT holidayname,
start_date,
end_date,
start_date - CASE TO_CHAR (start_date, 'Dy') WHEN 'Mon' THEN 3 WHEN 'Sun' THEN 2 ELSE 1 END AS prior_business_day
FROM holiday;
HOLIDAYNAME START_DATE END_DATE PRIOR_BUSINESS_DAY
______________ _____________ ____________ _____________________
holiday1 05-AUG-21 06-AUG-21 04-AUG-21
Christmas 25-DEC-21 26-DEC-21 24-DEC-21
July 4th 04-JUL-21 05-JUL-21 02-JUL-21
You can use a recursive sub-query factoring clause from this answer:
WITH start_date (dt) AS (
SELECT DATE '2021-05-02' FROM DUAL
),
days ( dt, day, found ) AS (
SELECT dt,
TRUNC(dt) - TRUNC(dt, 'IW'),
0
FROM start_date
UNION ALL
SELECT dt - CASE day WHEN 0 THEN 3 WHEN 6 THEN 2 ELSE 1 END,
CASE WHEN day IN (0, 6, 5) THEN 4 ELSE day - 1 END,
CASE WHEN h.start_date IS NULL THEN 1 ELSE 0 END
FROM days d
LEFT OUTER JOIN holidays h
ON ( dt - CASE day WHEN 0 THEN 3 WHEN 6 THEN 2 ELSE 1 END
BETWEEN h.start_date AND h.end_date )
WHERE found = 0
)
SELECT dt
FROM days
WHERE found = 1;
Which, for the sample data:
CREATE TABLE holidays (HolidayName, Start_date, End_Date) AS
SELECT 'holiday1', DATE '2021-08-05', DATE '2021-08-06' FROM DUAL;
Outputs:
DT
2021-08-04 00:00:00
db<>fiddle here
Don't know if it's very efficient. Did it just for fun
create table holidays (
holiday_name varchar2(100) primary key,
start_date date not null,
end_date date not null
)
/
Table created
insert into holidays (holiday_name, start_date, end_date)
values ('holiday1', date '2021-08-05', date '2021-08-06');
1 row inserted
with days_before(day, wrk_day) as
(select trunc(sysdate - 1) d,
case
when h.holiday_name is not null then 0
when to_char(trunc(sysdate - 1), 'D') in ('6', '7') then 0
else 1
end work_day
from dual
left join holidays h
on trunc(sysdate - 1) between h.start_date and h.end_date
union all
select db.day - 1,
case
when h.holiday_name is not null then 0
when to_char(db.day - 1, 'D') in ('6', '7') then 0
else 1
end work_day
from days_before db
left join holidays h
on db.day - 1 between h.start_date and h.end_date
where db.wrk_day = 0) search depth first by day set order_no
select day from days_before where wrk_day = 1;
DAY
-----------
04.08.2021

Calculate the number of days per month between two dates

Using Oracle 12c, I need to run a script on an existing summary table of projects. The summary table has a project, a start date, and an end date. I need to break this data out into the number of days per month for each project.
An example is Project A has a start date of 2/10/2016 and an end date of 3/10/2016. My ending result for this example should be:
Project A, February, 19
Project A, March, 10
This was an easier one as some dates may span 2 or 3 months. This doesn't seem too difficult but for some reason I'm having trouble wrapping my head around it and overthinking it. Does someone have an quick and easy solution to this? I would like to run this as a SQL statement but a PL/SQL script would also work.
In this solution we don't assume any prior knowledge of the time period covered. Also, this solution does not use joins (which may be important for performance).
with
-- begin test data (this section can be deleted)
inputs ( project, start_date, end_date ) as (
select 'A', date '2014-10-03', date '2014-12-15' from dual union all
select 'B', date '2015-03-01', date '2015-03-31' from dual union all
select 'C', date '2015-11-30', date '2016-03-01' from dual
),
-- end test data; solution begins here (it includes the word "with" from the first line)
prep ( project, end_date, dt ) as (
select project, end_date, start_date from inputs union all
select project, end_date, end_date + 1 from inputs union all
select project, end_date, add_months( trunc(start_date, 'mm'), level )
from inputs
connect by add_months (trunc(start_date, 'mm'), level) <= end_date
and prior project = project
and prior sys_guid() is not null
),
computations ( project, dt, month, day_count ) as (
select project, dt, to_char(dt, 'Mon-yyyy'),
lead(dt) over (partition by project order by dt) - dt
from prep
where dt <= end_date + 1
)
select project, month, day_count
from computations
where day_count > 0
order by project, dt
;
OUTPUT:
PROJECT MONTH DAY_COUNT
------- -------- ---------
A Oct-2014 29
A Nov-2014 30
A Dec-2014 15
B Mar-2015 31
C Nov-2015 1
C Dec-2015 31
C Jan-2016 31
C Feb-2016 29
C Mar-2016 1
9 rows selected
If you can do an assumption on the maximum number of days for a project (1000 in my example), you can use the following:
with yourTable(project, startDate, endDate) as
(
select 'Project a' as project,
date '2016-02-10' as startDate,
date '2016-03-10' as endDate
from dual
UNION ALL
select 'Project XX',
date '2016-01-01',
date '2016-01-10'
from dual
)
select project, to_char(startDate + n, 'MONTH'), count(1)
from yourTable
inner join (
select level n
from dual
connect by level <= 1000
)
on (startDate + n <= endDate)
group by project, to_char(startDate + n, 'MONTH')
The part with the CONNECT BY is used as a date generator, assuming that every project is at maximum 1000 days long; the external query uses the date generator to split the row of a project in many rows, one for each day between start and end date, and then aggregates by month and project to build the output.
A slightly different way, based on months and not days, could be:
select project, to_char(add_months(startDate, n ), 'MONTH'),
case
when trunc(add_months(startDate, n ), 'MONTH') = trunc(add_months(endDate, n ), 'MONTH')
then endDate - startDate +1
when trunc(add_months(startDate, n ), 'MONTH') <= startDate
then last_day(add_months(startDate, n)) - startDate
when last_day(add_months(startDate, n )) >= endDate
then endDate - trunc(add_months(startDate, n ), 'MONTH') +1
else
last_day(add_months(startDate, n )) - trunc(last_day(add_months(startDate, n )), 'MONTH')
end as numOfDays
from yourTable
inner join (
select level -1 n
from dual
connect by level <= 1000
)
on trunc(add_months(startDate, n ), 'MONTH') <= trunc(endDate, 'MONTH')
This is a bit more complicated, to handle the different cases, but more efficient, given that it works at month level, not day level
I think you're after something like:
WITH sample_data AS (SELECT 'A' PROJECT, to_date('10/02/2016', 'dd/mm/yyyy') start_date, to_date('10/03/2016', 'dd/mm/yyyy') end_date FROM dual UNION ALL
SELECT 'B' PROJECT, to_date('10/02/2016', 'dd/mm/yyyy') start_date, to_date('10/06/2016', 'dd/mm/yyyy') end_date FROM dual UNION ALL
SELECT 'C' PROJECT, to_date('10/02/2016', 'dd/mm/yyyy') start_date, to_date('18/02/2016', 'dd/mm/yyyy') end_date FROM dual)
SELECT PROJECT,
to_char(add_months(trunc(start_date, 'mm'), LEVEL -1), 'fmMonth yyyy', 'nls_date_language=english') mnth,
CASE WHEN trunc(end_date, 'mm') = add_months(trunc(start_date, 'mm'), LEVEL -1)
THEN end_date
ELSE add_months(trunc(start_date, 'mm'), LEVEL) -1
END - CASE WHEN trunc(start_date, 'mm') = add_months(trunc(start_date, 'mm'), LEVEL -1)
THEN start_date + 1
ELSE add_months(trunc(start_date, 'mm'), LEVEL -1)
END + 1 num_days
FROM sample_data
CONNECT BY PRIOR PROJECT = PROJECT
AND PRIOR sys_guid() IS NOT NULL
AND add_months(trunc(start_date, 'mm'), LEVEL -1) <= TRUNC(end_date, 'mm');
PROJECT MNTH NUM_DAYS
------- -------------- ----------
A February 2016 19
A March 2016 10
B February 2016 19
B March 2016 31
B April 2016 30
B May 2016 31
B June 2016 10
C February 2016 8
This uses the multi-row connect-by-level technique (the presence of the and prior sys_guid() is not null enables the connect by to loop through each row separately) to loop through each project row in the sample_data table (you presumably have the project information in a table already, so you wouldn't need to have the sample_data subquery at all; you could just reference your table directly in the main SQL).
We then compare the month of the start date with the month of the row being generated by the connect by, and if it's the same month, then we know we need to use the start date, otherwise we use the first of the month of the generated row; we do similarly for the end date.
That way, we can now subtract one from the other and make adjustments to make the calculation correct. You may need to tweak this yourself if you need a start and end date of the same day to count as 1 day, rather than 0 - it'll probably need an extra case statement to take account of when the start and end date are in the same month.
Using this approach won't limit your project length; it could be as long as you liked.
ETA: Looks like Mathguy posted an answer whilst I was typing out my answer, and whilst our basic methods are the same, mine doesn't use an analytic function to determine the difference in the number of days. You may or may not find their answer more performant than mine - you should test both to see which one works best with your data.

Retrieve rows with 0 count from Oracle

I am woking on a query which can give back the count divided by month about the offices that will be closed this summer.
SELECT
qa.tmonth,
COUNT(qa.tmonth) AS qtn
FROM
(
SELECT TO_CHAR(CLOSURE_DATE, 'yyyymm') AS tmonth
FROM Holidays
WHERE CLOSURE_DATE >= TO_DATE('20160501', 'YYYY-MM-DD') AND
CLOSURE_DATE <= TO_DATE('20160901', 'YYYY-MM-DD')
) qa
GROUP BY qa.tmonth;
Since the months: May, June, August and September no office will be closed the output is the following:
TMONTH|QTN
201607|80
But I need a thing like this
TMONTH|QTN
201605|0
201606|0
201607|80
201608|0
201609|0
How could I achieve that?
Thanks to all!
You can try with something like this:
SQL> with holidays(closure_date) as
2 (
3 select date '2016-07-01' from dual union all
4 select date '2016-07-02' from dual union all
5 select date '2016-07-03' from dual union all
6 select date '2016-07-04' from dual union all
7 select date '2016-07-05' from dual
8 )
9 select count(closure_date) as closure_days, to_char(day, 'yyyymm') as month
10 from (
11 select date '2016-05-01' + level -1 as day
12 from dual
13 connect by date '2016-05-01' + level -1 <= date '2016-09-30'
14 ) days
15 left outer join holidays
16 on (day = closure_date)
17 group by to_char(day, 'yyyymm') ;
CLOSURE_DAYS MONTH
------------ ------
0 201608
5 201607
0 201606
0 201605
0 201609
SQL>
This uses a query to build the list of all the days between a starting and an ending date; I used 01/05 and 30/09 and called it days.
Then it queries days with the holidays table in outer join; this way you can count only the days for which there is a corrensponding value in the closure days list, thus counting the closure days for each day, month year; the aggregation for year and month completes the job
A similar approach like above. Tip: You can execute the two sub-queries separately, to analyse the logic.
select to_char (m.month, 'yyyymm') as TMONTH, m.month,
nvl (h.qtn, 0) as QTN
from
(
SELECT add_months(trunc (SYSDATE, 'MONTH'), -(LEVEL-1)) as MONTH
FROM dual
CONNECT BY LEVEL <= 12 -- generate a list of the last 12 month
) m
left join
(
SELECT trunc (closure_date, 'MONTH') as MONTH,
count (*) as QTN
FROM Holidays
group by trunc (closure_date, 'MONTH')
) h
on m.MONTH = h.MONTH
where m.month between DATE '2016-01-01' and sysdate
order by TMONTH desc;

Get First Day Of Week From Week Number

In Oracle, is there a straightforward way to get the first day of the week given a week number?
For example, today's date is 12/4/2012. If I run:
select to_char(sysdate,'WW') from dual;
It returns 49 for the week number.
What I would like to do is somehow return 12/2/2012 for the first day...given week 49 (assuming Sunday as first day of the week).
Any ideas? Thanks in advance for any help!
try this:
select next_day(max(d), 'sun') requested_sun
from (select to_date('01-01-2012', 'dd-mm-yyyy') + (rownum-1) d from dual connect by level <= 366)
where to_char(d, 'ww') = 49-1;
just set your year to_date('01-01-2012' and week number-1 49-1 as applicable.
the sunday in the 49th week of 2008?
SQL> select next_day(max(d), 'sun') requested_sun
2 from (select to_date('01-01-2008', 'dd-mm-yyyy') + (rownum-1) d from dual connect by level <= 366)
3 where to_char(d, 'ww') = 49-1;
REQUESTED
---------
07-DEC-08
and 2012
SQL> select next_day(max(d), 'sun') requested_sun
2 from (select to_date('01-01-2012', 'dd-mm-yyyy') + (rownum-1) d from dual connect by level <= 366)
3 where to_char(d, 'ww') = 49-1;
REQUESTED
---------
02-DEC-12
Try this,
select
next_day(trunc(to_date(in_year,'yyyy'),'yyyy') -1,'Mon') + (7 * (in_week - 1))
from dual;
If you have the date, not just the week number, you can try this:
Get the day number of the week of your date with: to_char(theDate, 'D')
substract that number from your date plus 1, and you'll get the Sunday of that week.
Add 7 and you'll get the date of end of the week(Saturday).
Like this:
SELECT theDate - to_char(theDate, 'D') + 1 as BeginOfWeek,
theDate,
theDate - to_char(theDate, 'D') + 7 as EndOfWeek
FROM TableName
I can't comment on questions yet, so I'll add another one. But this is based on #Dazzals answer.
His solution doesn't work for week one and for ISO-weeks. Also it doesn't work, if the first day of the week is not sunday, which can be controlled by NLS_SETTINGS.
This one does:
SELECT MIN(D)
FROM (SELECT TO_DATE('01-01-2013', 'dd-mm-yyyy') + (ROWNUM-10) D, ROWNUM R
FROM DUAL
CONNECT BY LEVEL <= 376)
WHERE TO_CHAR(D,'IYYYIW') = '201301'
Because we are spanning more than one year, we need to check the year too.
Using the trunc function #Justin used, I think this is what you want:
select trunc(to_date('2012-01-01', 'YYYY-MM-DD') + (49 - 1) * 7, 'WW') from dual;
I ended up doing this:
function getFirstDayOfWeek(y in binary_integer, w in binary_integer) return date
is
td date;
begin
td:=TO_DATE(TO_CHAR(y)||'0101', 'YYYYMMDD');
for c in 0..52
loop
if TO_NUMBER(TO_CHAR(td, 'IW'))=w then
return TRUNC(td, 'IW');
end if;
td:=td+7;
end loop;
return null;
end;

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