Question

I have a table that lists month totals (targets)

person      total                 month       
----------- --------------------- ----------- 
1001        114.00                201005      
1001        120.00                201006      
1001        120.00                201007      
1001        120.00                201008      
.
1002        114.00                201005      
1002        222.00                201006      
1002        333.00                201007      
1002        111.00                201008      
.
.

but month is an integer(!)

I also have another table that has a list of working days (calendar)

tran_date               day_type
----------------------- ---------------------------------
1999-05-01 00:00:00.000 WEEKEND
1999-05-02 00:00:00.000 WEEKEND
1999-05-03 00:00:00.000 WORKING_DAY
1999-05-04 00:00:00.000 WORKING_DAY

1999-06-01 00:00:00.000 .....
.
.
.

What I want to do is get a list of dates with the average for that day based on the number of days in the month where day_type is ‘WORKING_DAY’ / the month’s total.

so if I had say 20 working days in 201005 then I’d get an average of 114/20 on each working day, while the other days would be 0.

somthing like

person   tran_date               day_avg
-------  ----------------------- ---------------------------------
1001     2010-05-01 00:00:00.000 0
1001     2010-05-02 00:00:00.000 0
1001     2010-05-03 00:00:00.000 114/2 (as there are two working days)
1001     2010-05-04 00:00:00.000 114/2 (as there are two working days)
.
.
.

It has to be done as a CTE as this is a limitation of the target system (I can only do one statement)
I can start off with (Dates to

WITH 
Dates AS
(
    SELECT CAST('19990501' as datetime) TRAN_DATE
    UNION ALL
    SELECT TRAN_DATE + 1
    FROM Dates
    WHERE TRAN_DATE + 1 <= CAST('20120430' as datetime)
),
Targets as
(
   select CAST(cast(month as nvarchar) + '01' as dateTime) mon_start, 
            DATEADD(MONTH, 1, CAST(cast(month as nvarchar) + '01' as dateTime)) mon_end, 
             total
   from targets
)
select ????

Answer 1

Sample data (may vary):

select * into #totals from (
select '1001' as person, 114.00  as total, 199905 as month union
select '1001', 120.00, 199906 union
select '1001', 120.00, 199907 union
select '1001', 120.00, 199908  

) t

select * into #calendar from (
select cast('19990501' as datetime) as tran_date, 'WEEKEND' as day_type union
select '19990502', 'WEEKEND' union
select '19990503', 'WORKING_DAY' union
select '19990504', 'WORKING_DAY' union
select '19990505', 'WORKING_DAY' union
select '19990601', 'WEEKEND' union
select '19990602', 'WORKING_DAY' union
select '19990603', 'WORKING_DAY' union
select '19990604', 'WORKING_DAY' union
select '19990605', 'WORKING_DAY' union
select '19990606', 'WORKING_DAY' union
select '19990701', 'WORKING_DAY' union
select '19990702', 'WEEKEND' union
select '19990703', 'WEEKEND' union
select '19990704', 'WORKING_DAY' union
select '19990801', 'WORKING_DAY' union
select '19990802', 'WORKING_DAY' union
select '19990803', 'WEEKEND' union
select '19990804', 'WEEKEND' union
select '19990805', 'WORKING_DAY' union
select '19990901', 'WORKING_DAY'
) t

Select statement, it returns 0 if the day is ‘weekend’ or not exists in calendar table. Please keep in mind that MAXRECURSION is a value between 0 and 32,767.

;with dates as ( 
    select cast('19990501' as datetime) as tran_date 
    union all 
    select dateadd(dd, 1, tran_date) 
    from dates where dateadd(dd, 1, tran_date) <= cast('20010101' as datetime) 
) 
select t.person , d.tran_date, (case when wd.tran_date is not null then t.total / w_days else 0 end) as day_avg 
from dates d 
left join #totals t on  
    datepart(yy, d.tran_date) * 100 + datepart(mm, d.tran_date) = t.month 
left join ( 
        select datepart(yy, tran_date) * 100 + datepart(mm, tran_date) as month, count(*) as w_days 
        from #calendar 
        where day_type = 'WORKING_DAY' 
        group by datepart(yy, tran_date) * 100 + datepart(mm, tran_date) 
) c on t.month = c.month  
left join #calendar wd on d.tran_date = wd.tran_date and wd.day_type = 'WORKING_DAY' 
where t.person is not null
option(maxrecursion 20000)