How to get biggest value from 2 or more fields in a subquery - sql

Question

I have a table with customers that I join with a fact table with sales, based on invoices.
What I need from my report is to get in first part the biggest value of sales based on the incoming order type (1,2,3,C,D) for a customer for last year. And in the second part to get the same but for current year. What I get as result from my current query is all incoming order types with the customer revenue made for each of them. I tried with outer apply as subquery to get only the top 1 value ordered by revenue descending, but in the result I get the same - For all order types the customer revenue. Please help! I hope my explanation isn't understood only by me (happens a lot..)
use dwh01;
WITH OrderTypeUsedLY AS
(
SELECT
c.CustomerKey
,c.BranchId
,c.CustomerId
,c.CustomerName
,ISNULL(SUM(y.[Sale_Revenue]), 0) as [Sale_Revenue_LY]
,ISNULL(SUM(y.[Sale_GrossMarginTotal]), 0) as [Sale_GrossMarginTotal_LY]
,y.IncomingOrderTypeId as IncomingOrderType_LY
FROM live.DimCustomer c
left join (SELECT s.CustomerKey,iot.IncomingOrderTypeid, s.[Sale_Revenue], s.[Sale_GrossMarginTotal] FROM [dwh01].[live].[FactSales] s
inner join live.DimDate d
on d.DateId = s.PostingDateKey
inner join live.DimIncomingOrderType iot on iot.IncomingOrderTypeKey = s.IncomingOrderTypeKey
where s.ReportCurrencyId = 'LC'
and D.Year = YEAR(GETDATE())-1 --- Last Year
) y on c.CustomerKey = y.CustomerKey
where c.CustomerKey = '157053'
group by c.CustomerKey, c.CustomerId, c.CustomerName, c.BranchId, y.IncomingOrderTypeId
),
--*********************************************************************************************************************************--
OrderTypeCY as(
SELECT
c.CustomerKey
,c.BranchId
,c.SalesRepKey
,c.CustomerId
,c.CustomerName
,ISNULL(SUM(y.[Sale_Revenue]), 0) as [Sale_Revenue_CY]
,ISNULL(SUM(y.[Sale_GrossMarginTotal]), 0) as [Sale_GrossMarginTotal_CY]
,y.IncomingOrderTypeId as IncomingOrderType_CY
FROM live.DimCustomer c
left join (SELECT s.CustomerKey,iot.IncomingOrderTypeid, s.[Sale_Revenue], s.[Sale_GrossMarginTotal] FROM [dwh01].[live].[FactSales] s
inner join live.DimDate d
on d.DateId = s.PostingDateKey
inner join live.DimIncomingOrderType iot on iot.IncomingOrderTypeKey = s.IncomingOrderTypeKey
where s.ReportCurrencyId = 'LC'
and D.Year = YEAR(GETDATE()) --- Current Year
) y on c.CustomerKey = y.CustomerKey
where c.CustomerKey = '157053'
group by c.CustomerKey, c.CustomerId, c.CustomerName, c.BranchId, y.IncomingOrderTypeId, c.SalesRepKey
)
--*********************************************************************************************************************************--
SELECT
otly.BranchId,
rep.SalesRepId,
rep.SalesRepName,
otly.CustomerId,
otly.CustomerName,
otly.Sale_Revenue_LY,
otly.Sale_GrossMarginTotal_LY,
IncomingOrderType_LY,
otcy.Sale_Revenue_CY,
otcy.Sale_GrossMarginTotal_CY,
IncomingOrderType_CY
from OrderTypeUsedLY otly
left join OrderTypeCY otcy
on otly.CustomerKey = otcy.CustomerKey
join live.DimCustomer cus on cus.CustomerKey = otcy.CustomerKey
join live.DimSalesRep rep on rep.SalesRepKey = otcy.SalesRepKey
order by otcy.Sale_Revenue_CY desc, otly.Sale_Revenue_LY desc
,rep.SalesRepId
And here is the outer apply I tried:
outer apply (
SELECT top 1
iot.IncomingOrderTypeId,
Sale_Revenue
FROM [dwh01].[live].DimIncomingOrderType iot
where iot.IncomingOrderTypeKey = y.IncomingOrderTypeKey
order by Sale_Revenue desc) x
In the first select ( with OrderTypeUsed_LY ) I get this:
And I get the same in the second select, but with the values for current year.
The purpose of the report is to see the difference in the incoming order type most used (most profit made with it) for a customer last year and to see if he continues to use it this year, or uses another incoming order type this year.
Again I'm sorry for the bad explanation, I'm trying my best (I understand myself very well)
Here is the expected result:
Expected Result
I marked in red the last year part and in green the current year part.

Answer 1

If you change the subquery to:
SELECT
iot.IncomingOrderTypeKey,
MAX(Sale_Revenue)
FROM [dwh01].[live].DimIncomingOrderType iot
GROUP BY iot.IncomingOrderTypeKey
then you can JOIN (not APPLY) directly on IncomingOrderTypeKey AND Sale_Revenue.

Answer 2

Try this:
USE dwh01;
DECLARE #CustomerKey varchar(6) = '157053'
, #ReportCurrencyId varchar(2) = 'LC'
, #CurrentYear int = YEAR(GETDATE())
, #TargetYear int = YEAR(GETDATE())-1
;
WITH FactsTable AS
(
SELECT
s.CustomerKey
, i.IncomingOrderTypeid
, [Sale_Revenue] = ISNULL(s.[Sale_Revenue] , 0)
, [Sale_GrossMarginTotal] = ISNULL(s.[Sale_GrossMarginTotal], 0)
, d.[Year]
FROM [dwh01].[live].[FactSales] s
inner join live.DimDate d on d.DateId = s.PostingDateKey
inner join live.DimIncomingOrderType i on i.IncomingOrderTypeKey = s.IncomingOrderTypeKey
where
s.CustomerKey = #CustomerKey
and s.ReportCurrencyId = #ReportCurrencyId
)
, OrderTypeTable
(
SELECT
c.CustomerKey
, c.BranchId
, c.CustomerId
, c.CustomerName
, c.SalesRepKey
, IncomingOrderType_LY = SUM(CASE WHEN y.[Year] = #TargetYear THEN y.IncomingOrderTypeId ELSE 0 END)
, [Sale_Revenue_LY] = SUM(CASE WHEN y.[Year] = #TargetYear THEN y.[Sale_Revenue] ELSE 0 END)
, [Sale_GrossMarginTotal_LY] = SUM(CASE WHEN y.[Year] = #TargetYear THEN y.[Sale_GrossMarginTotal] ELSE 0 END)
, IncomingOrderType_LY = SUM(CASE WHEN y.[Year] = #CurrentYear THEN y.IncomingOrderTypeId ELSE 0 END)
, [Sale_Revenue_CY] = SUM(CASE WHEN y.[Year] = #CurrentYear THEN y.[Sale_Revenue] ELSE 0 END)
, [Sale_GrossMarginTotal_CY] = SUM(CASE WHEN y.[Year] = #CurrentYear THEN y.[Sale_GrossMarginTotal] ELSE 0 END)
FROM live.DimCustomer c
left join FactsTable y on y.CustomerKey = c.CustomerKey
group by
c.CustomerKey
, c.BranchId
, c.CustomerId
, c.CustomerName
, y.IncomingOrderTypeId
, c.SalesRepKey
)
SELECT
O.BranchId
, R.SalesRepId
, R.SalesRepName
, O.CustomerId
, O.CustomerName
, O.Sale_Revenue_LY
, O.Sale_GrossMarginTotal_LY
, O.IncomingOrderType_LY
, O.Sale_Revenue_CY
, O..Sale_GrossMarginTotal_CY
, O.IncomingOrderType_CY
from OrderTypeTable O
join live.DimSalesRep R on R.SalesRepKey = O.SalesRepKey
order by
O.Sale_Revenue_CY desc
, O.Sale_Revenue_LY desc
, R.SalesRepId

Answer 3

The solution is with using row_number() function in the inner query of the first CTE:
(
select *, row_number() over (partition by x0.CustomerKey order by x0.Sale_Revenue desc) as rn
from
(
select fs.CustomerKey, iot.IncomingOrderTypeKey,
sum(fs.Sale_Revenue) as Sale_Revenue
FROM [dwh01].[live].DimIncomingOrderType iot
join live.FactSales fs
on iot.IncomingOrderTypeKey = fs.IncomingOrderTypeKey
join live.DimDate d
on d.DateId = fs.PostingDateKey
where d.[year] = #CurrentYear
GROUP BY fs.CustomerKey, iot.IncomingOrderTypeKey
) as x0
) as x1 on x1.CustomerKey = s.CustomerKey
The row_number() function gets only the first row from the result for each customer, and that is with the biggest sale revenue ( order by sale_revenue desc).