A query with workingdays per month per persons per period

Question

Can anyone help me on the way in building a difficult SQL query?
I work with Oracle SQL. It is intended to calculate over a certain period, to find the working days for each month for each person.
I have a working query for calculate the number of days for 1 months minus holidays
Select count (*) NUM_WORK_DAYS
From (
Select to_date ('01-01-2010 ',' dd-mm-yyyy ') + ROWNUM-1 as day
From all_objects
Where ROWNUM <to_number (to_char (last_day ('01-01-2010 '), DD')) + 1)
Where to_number (to_char (day, 'd')) between 1 and 5
And not exists (select NULL
From HOLIDAY
Where Holiday.hol=day)
There is a datetable with the following structure where I can get the periods:
DATES
YEAR | MONTH | WEEK | SD
2010 | 201002 | 201006 | 09/02/2010
All required months are present
It is intended that the user give a beginning and a end time specify.
I have a table of workingdays per person named
CALENDAR
CAL | MON | TUE | WED | THU | FRI | SAT | SUN
Person | Y | Y | N | Y | Y | N | N
And a table of holidays
HOLIDAY
CAL | HOL
Person | 01/01/2010
How can I combine the query for working days and build a query that returns for multiple people over multiple months the number of workingdays per month? I will ask the user to give a beginning period and a end period
I am aware that I ask a lot of your time, but I can not imagine the solution myself. Many thanks in advance
Gr,
Els

Answer 1

You can do something like this:
SQL> select * from calendar;
    PERSON M T W T F S S
         1 Y Y N Y Y N N
         2 Y Y Y Y Y N N
SQL> select * from holiday;
    PERSON HOL
         1 12-FEB-10
         2 09-FEB-10
SQL> define start_day=2010-02-01
SQL> define end_day=2010-02-20
SQL> with period as (
  2  select DATE '&start_day' start_date, DATE '&end_day' end_date
  3    from dual),
  4  days as (
  5  select start_date+level-1 day
  6    from dual,period
  7  connect by level <= end_date-start_date+1),
  8  mycal as (
  9  select person, 'monday' day, mon works from calendar union all
10  select person, 'tuesday' day, tue from calendar union all
11  select person, 'wednesday' day, wed from calendar union all
12  select person, 'thursday' day, thu from calendar union all
13  select person, 'friday' day, fri from calendar union all
14  select person, 'saturday' day, sat from calendar union all
15  select person, 'sunday' day, sun from calendar
16  )
17  select person, count(0)
18    from mycal c, days d
19   where c.day = trim(to_char(d.day,'day'))
20     and c.works='Y'
21     and not exists (select 1 from holiday h where h.person=c.person and h.hol=d.day)
22  group by person;
old   2: select DATE '&start_day' start_date, DATE '&end_day' end_date
new   2: select DATE '2010-02-01' start_date, DATE '2010-02-20' end_date
    PERSON   COUNT(0)
         1         11
         2         14The PERIOD view is there only to accept start and end date.
The DAYS view contains all the days of the period
The MYCAL view unpivotes the calendar days returning 7 rows for each person, a row per weekday
Max
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