SQL Aggregate function: Sum of some rows in another row - sql

Question

I have following scenario with sql server 2008
**** Original Result ****
================================================
Year month Category Count_days
================================================
2001 09 Leave 03
2001 09 Worked Below 8hrs 18
2001 09 Worked Above 8hrs 05
2001 09 Present 0 <----- current value
2001 10 Leave 01
2001 10 Worked Below 8hrs 10
2001 10 Worked Above 8hrs 09
2001 10 Present 0 <------ current value
Following is the criteria
criteria
===========
Present Count of 'x'th Month = SUM(Worked Below 8hrs count of 'x'th month) +
SUM(Worked Above 8hrs count of 'x'th month )
;where x is the month
I want following result with satisfying above criteria
**** Expected Result ****
===============================================
Year month Category Count_days
================================================
2001 09 Leave 03
2001 09 Worked Below 8hrs 18
2001 09 Worked Above 8hrs 05
2001 09 Present 23 <-----(expecting sum 18+05 =23)
2001 10 Leave 01
2001 10 Worked Below 8hrs 10
2001 10 Worked Above 8hrs 09
2001 10 Present 19 <-----(expecting sum 10+09 = 19)
Problem is the original result is generated by very complex query hence cant call same set again i.e.
Cannot use this (This will hamper the performance of my application.)
=================
select * from original (some join) select * from original
may be need to use the single query or It can be subquery, use of aggregate function etc.
Expecting any aggregation trick to generate my expected result????
Please help me out guys....

Answer 1

you can use sum as analytic function
SELECT
year, month, cat, count_days as count_days_orig,
case cat
when 'Present'
then
sum (
case
when cat in ('Worked Below 8hrs', 'Worked Above 8hrs')
then count_days
else 0
end
)
over (partition by year, month)
else count_days
end as count_days_calc
FROM
(
SELECT 2001 as year, 09 as month , 'Leave ' as cat , 03 as count_days FROM dual
UNION all
SELECT 2001 as year, 09 as month , 'Worked Below 8hrs' as cat , 18 as count_days FROM dual
UNION all
SELECT 2001 as year, 09 as month , 'Worked Above 8hrs' as cat , 05 as count_days FROM dual
UNION all
SELECT 2001 as year, 09 as month , 'Present' as cat , 0 as count_days FROM dual
UNION all
SELECT 2001 as year, 10 as month , 'Leave ' as cat , 01 as count_days FROM dual
UNION all
SELECT 2001 as year, 10 as month , 'Worked Below 8hrs' as cat , 10 as count_days FROM dual
UNION all
SELECT 2001 as year, 10 as month , 'Worked Above 8hrs' as cat , 09 as count_days FROM dual
UNION all
SELECT 2001 as year, 10 as month , 'Present' as cat , 0 as count_days FROM dual
)
;
year month cat count_days_orig count_days_calc
--------------------------------------------------------------------------
2001 9 Leave 3 3
2001 9 Worked Below 8hrs 18 18
2001 9 Worked Above 8hrs 5 5
2001 9 Present 0 23
2001 10 Leave 1 1
2001 10 Worked Below 8hrs 10 10
2001 10 Worked Above 8hrs 9 9
2001 10 Present 0 19

Answer 2

Something like this, don't know if column names are correct and stuff.
SELECT Year, month, category,
CASE Category
WHEN 'Present'
THEN (
SELECT Sum(T2.Count_days)
FROM table T2
WHERE T2.year = T.year
AND T2.month = T.month
AND T2.Category NOT IN ('Present', 'Leave')
)
ELSE Count_days
END
FROM table T
But this really feels like a wrong design...