How to get the Average from two tables SQL - sql-server

Question

I have 2 tables Denials_Scrub_Final and Claims_Final
I want to get the percent for all the invoice.
That would be (Denials_Scub_Final/Claims_Final) *100
This would display a new table Percentage as a new table.
This should look like the excel screenshot which was manually done.
Last block Denial Rate.

Answer 1

No final solution, but the approach should be clear.
Since we do not have the data from Denials_Scrub_Final or Claims_Final I generated some sample data. I am using a single table variable #data with some duplicates to generate the different numbers.
-- create sample data
declare #data table
(
Yr int,
Mth int,
Center nvarchar(10),
Invoice int
);
insert into #data (Yr, Mth, Center, Invoice) values
(2020, 1, 'ABC', 101),
(2020, 1, 'ABC', 101),
(2020, 1, 'ABC', 102),
(2020, 1, 'DEF', 201),
(2020, 1, 'DEF', 202),
(2020, 2, 'ABC', 103),
(2020, 2, 'ABC', 104),
(2020, 2, 'DEF', 203),
(2020, 3, 'ABC', 105),
(2020, 3, 'ABC', 105),
(2020, 3, 'ABC', 106),
(2020, 2, 'DEF', 204),
(2020, 2, 'DEF', 204),
(2020, 2, 'DEF', 205);
The first data set:
-- reproduce first query
select *
from ( select distinct Invoice, Center, Yr, Mth from #data ) BaseData
pivot ( count(Invoice) for Center in ([ABC], [DEF]) ) p;
gives
Yr Mth ABC DEF
----------- ----------- ----------- -----------
2020 1 2 2
2020 2 2 3
2020 3 2 0
The second data set:
-- reproduce second query
select *
from ( select Invoice, Center, Yr, Mth from #data ) BaseData
pivot ( count(Invoice) for Center in ([ABC], [DEF]) ) p;
gives
Yr Mth ABC DEF
----------- ----------- ----------- -----------
2020 1 3 2
2020 2 2 4
2020 3 3 0
Final solution: move the data sets in common table expressions (CTE's) and join them to apply the formula (use case to avoid division by zero and convert to format the percentages):
-- combine queries in CTE's and apply formula
with cte_denial as
(
select p.Yr, p.Mth, p.ABC, p.DEF
from ( select distinct Invoice, Center, Yr, Mth from #data ) BaseData
pivot ( count(Invoice) for Center in ([ABC], [DEF]) ) p
),
cte_claim as
(
select p.Yr, p.Mth, p.ABC, p.DEF
from ( select Invoice, Center, Yr, Mth from #data ) BaseData
pivot ( count(Invoice) for Center in ([ABC], [DEF]) ) p
)
select c1.Yr,
c1.Mth,
convert(numeric(5,2), case when c2.ABC > 0 then c1.ABC*100.0/c2.ABC else 0 end) as 'ABC_%',
convert(numeric(5,2), case when c2.DEF > 0 then c1.DEF*100.0/c2.DEF else 0 end) as 'DEF_%'
from cte_denial c1
join cte_claim c2
on c2.Yr = c1.Yr
and c2.Mth = c1.Mth;
gives
Yr Mth ABC_% DEF_%
----------- ----------- ---------- ----------
2020 1 66.67 100.00
2020 2 100.00 75.00
2020 3 66.67 0.00