Conditional sum and count in Teradata (SQL help) - sql

Question

My data is setup in the following way:
Person Account Revenue Region
A W 100 AU
A W 200 AU
A W 300 AU
B X 200 AU
B X 50 CH
B X 50 CH
Here is code for the sample data:
IF OBJECT_ID('tempdb..#StackTest') IS NOT NULL
DROP TABLE #StackTest;
CREATE TABLE #StackTest
(Person varchar(1)
, Account varchar(1)
, Revenue int
, Region varchar(2));
INSERT INTO #StackTest
(Person
, Account
, Revenue
, Region)
VALUES
('A', 'W', 100, 'AU'),
('A', 'W', 200, 'AU'),
('A', 'W', 300, 'AU'),
('B', 'X', 200, 'AU'),
('B', 'X', 50, 'CH'),
('B', 'X', 50, 'CH');
I need to write a SQL query that sums revenue for only those accounts when total sum of an account Q exceeds Y. Similarly, I also need to count only those accounts when total sum of an account Q exceeds Y. So if my sum threshold for region AU is 500 and for region CH is 200, then I would want the following output
Output # of accounts exceeding threshold sum Revenue from these accounts
A 1 600
B 0 0
However, my current query is checking each line item separately and not at the account level.
What should I do?

Answer 1

In standard SQL, you would use two levels of aggregation. I suspect that the query is something like:
select person,
sum(case when region = 'AU' and revenue > 500 then 1
when region = 'CH' and revenue > 200 then 1
else 0
end) as numAccounts,
sum(case when region = 'AU' and revenue > 500 then revenue
when region = 'CH' and revenue > 200 then revenue
else 0
end) as reveue,
from (select person, region, sum(revenue) as revenue
from t
group by person, region
) t
group by person;

Answer 2

The following query will aggregate by person/region, and then apply regional thresholds from separate table in order to generate results.
Updated to account for separate regional thresholds
IF OBJECT_ID('tempdb..#Thresholds') IS NOT NULL
DROP TABLE #Thresholds
CREATE TABLE #Thresholds (Region VARCHAR(2), Revenue INT)
INSERT #Thresholds VALUES ('AU', 500), ('CH', 200)
--DECLARE #Threshold INT = 500
SELECT
T.Person,
SUM(CASE WHEN T.[Revenue] >= Thresholds.Revenue THEN T.[Count] ELSE 0 END) AS [# of accounts exceeding threshold sum],
SUM(CASE WHEN T.[Revenue] >= Thresholds.Revenue THEN T.[Revenue] ELSE 0 END) AS [Revenue from these accounts]
FROM (
SELECT
Person,
Region, -- Add region to apply thresholds by region
COUNT(DISTINCT Account) AS [Count],
SUM(Revenue) AS [Revenue]
FROM #StackTest
GROUP BY Person, Region
) T
INNER JOIN #Thresholds Thresholds
ON Thresholds.Region = T.Region
GROUP BY Person
ORDER BY Person