TSQL-2008 SUM(X) OVER (PARTITION … ORDER BY CLAUSE)

Question

I really need to take what I have as a result of a CTE, and calculate the cummulative value of groups of data.

The dataset is:

PERIOD  FT  GROUP   DEPT           


        

Answer 1

This should work. (I changed a forbidden column name from "GROUP" to "GROUP_")

with cte (PERIOD,  FT,  GROUP_,   DEPT,   VALUE, AccValue) as (select t1.PERIOD,  t1.FT,  t1.GROUP_,   t1.DEPT,    t1.VALUE, SUM(t2.VALUE)   as AccValue
                            from            myTable t1
                            join myTable t2 on t1.PERIOD>= t2.PERIOD
                            and  t1.FT =  t2.FT 
                            and t1.GROUP_ = t2.GROUP_           
                            and t1.DEPT = t2.DEPT
                            group by    t1.PERIOD,  t1.FT,  t1.GROUP_,   t1.DEPT,    t1.VALUE
                    )
                                select  PERIOD
                    ,FT
                    ,GROUP_
                    ,DEPT
                    ,VALUE
                    ,CASE
                        WHEN FT = 'Actual' THEN AccValue
                        ELSE VALUE
                        END AS AccValue 
                        from cte
                                order by GROUP_ desc,  FT, PERIOD, DEPT desc,    VALUE