SQL:Pivot table which includes sum and percentage total - sql

Question

I'm trying to recreate a view in Tableau as a view in SQL. It requires me pivoting a table based on month and not only summing the amount but I also need to sum by margin and also create a Margin % row.The desired output is
BUSINESS_UNIT CLASS JANUARY FEBRUARY MARCH
202 Cost of Sales 100 (null) 60
202 Revenue 200 80 (null)
202 Margin x xx xxx
202 Margin % x% xx% xxx%
I can pivot based on Month but how do perform twos sums in one pivot table and how would I go about including a percenatge row also?
Code so far
SELECT
*
FROM
(SELECT
[Business_Unit]
,[Class]
,Month as Period
,[Amount]
--,Margin
FROM [sample_table]
where [Class] in ('Revenue','Cost of Sales') )AS T
PIVOT(SUM(Amount)
FOR Period IN ([January],[February],[March])) as Pvt
I have included my code so far http://www.sqlfiddle.com/#!3/06bafc/6

Answer 1

Not the prettiest SQL I've done. but this seems to work...
http://www.sqlfiddle.com/#!3/06bafc/60/0
What it does is build on what you've done by generating a margin line and adding a total column
Using this line and total we can then calculate the % of margin. Grouping SETS allowed me to generate the multiple rows, subtotals and totals, Since I knew the only additional line generated would have a null class, I was able to set the Name of the class to margin when null.
WITH CTE AS (
SELECT
Business_Unit
,case when class is NULL then 'Margin' else class end as Class
,Sum(January) as January
,Sum(February) as February
,Sum(March) as march
,Sum(coalesce(January,0)+coalesce(February,0)+coalesce(March,0)) as Total
FROM (
SELECT
*
FROM
(SELECT
[Business_Unit]
,[Class]
,Month as Period
,[Amount]
--,Margin
FROM [sample_table]
where [Class] in ('Revenue','Cost of Sales') )AS T
PIVOT(SUM(Amount)
FOR Period IN ([January],[February],[March])) as Pvt
) as Base
GROUP BY Grouping sets
((Business_Unit,Class,January,February,March,
coalesce(January,0)+coalesce(February,0)+coalesce(March,0))
,(Business_Unit)
))
SELECT *
FROM CTE UNION
SELECT Business_Unit
,'Margin %'
,January*100.00/Total
,February*100.00/Total
,March*100.00/Total
,Total*100.00/Total
FROM CTE
WHERE CLASS='Margin'