How to calculate and update subtotal in SQL Server table - sql

Question

I have a SQL Server table in following format: Type column is to indicate whether row is Subtotal or line level value.
If type is 1, then it is line level cost, and if type is 2, then it is subtotal and if type is 3, then it is grand total.
Category Subcategory Option1 Option2 Option3 Option4 Type
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Insurance Insurance Cost 10 20 30 40 1
Insurance Insurance Tax 10 20 30 40 1
Insurance Subtotal 0 0 0 0 2
Finance Finance Cost 10 20 30 40 1
Finance Finance Tax 10 20 30 40 1
Finance Subtotal 0 0 0 0 2
GrandTotal GrandTotal 0 0 0 0 3
----------------------------------------------------------------------------
I want to update rows with subtotal with line level subtotal of respective category and grand total with line level total
Category Subcategory Option1 Option2 Option3 Option4 Type
----------------------------------------------------------------------------
Insurance Insurance Cost 10 20 30 40 1
Insurance Insurance Tax 10 20 30 40 1
Insurance Subtotal 20 40 60 80 2
Finance Finance Cost 10 20 30 40 1
Finance Finance Tax 10 20 30 40 1
Finance Subtotal 20 40 60 80 2
GrandTotal GrandTotal 40 80 120 160 3
----------------------------------------------------------------------------
How can I calculate and update these rows?
Awaiting for your reply.
Thanks.

Answer 1

I think cube extension for group by best suites for your case. Consider :
select distinct max(Category) as Category, Subcategory,
sum(Option1) as Option1
sum(Option2) as Option2,
sum(Option3) as Option3,
sum(Option4) as Option4
from t
where type = 1
group by cube(Category,Subcategory)
order by Category, Subcategory desc;
Rextester Demo "This is for Option1 column only, expandable for other options"
P.S. it's illogical to store a computable data in a table, that could already exist as basic data in that table as #Dougie pointed out.

Answer 2

You are trying to do an update, so that is a bit tricky. I think this will do the trick:
update t
set option1 = (case t.subcategory
when 'Subtotal' then subtotal.option1
when 'GrandTotal' then grandtotal.option1
else option1
end),
option2 = (case t.subcategory
when 'Subtotal' then subtotal.option2
when 'GrandTotal' then grandtotal.option2
else option2
end),
option3 = (case t.subcategory
when 'Subtotal' then subtotal.option3
when 'GrandTotal' then grandtotal.option3
else option3
end),
option4 = (case t.subcategory
when 'Subtotal' then subtotal.option4
when 'GrandTotal' then grandtotal.option4
else option4
end)
from t cross apply
(select category, sum(option1) as option1, sum(option2) as option2,
sum(option3) as option3)
from t t2
where t2.category = t.category
) subtotal cross join
(select category, sum(option1) as option1, sum(option2) as option2,
sum(option3) as option3)
from t t2
) grandtotal
where t.subcategory in ('Subtotal', 'GrandTotal');