Loop through multiple columns with case-then - sql

Question

I am using oracle sql developer and have a query whereby I want to apply the same query on different columns, then stack the resulting output into a single data table.
For example, the query looks like the following:
select BG_TURNOVER, MARKET, count(*)
FROM( SELECT (CASE
WHEN sports_returns_l90d = 0
THEN 'sports_returns_l90d_0'
WHEN sports_returns_l90d > 0 AND sports_returns_l90d <= 500
THEN 'sports_returns_l90d_0_500'
WHEN sports_returns_l90d > 500 AND sports_returns_l90d <= 1000
THEN 'sports_returns_l90d_500_1000'
WHEN sports_returns_l90d > 1000 AND sports_returns_l90d <= 2500
THEN 'sports_returns_l90d_1000_2500'
WHEN sports_returns_l90d > 2500 AND sports_returns_l90d <= 5000
THEN 'sports_returns_l90d_2500_5000'
ELSE 'sports_returns_l90d_5000+'
END) AS BG_TURNOVER, MARKET
FROM PRODUCT_TABLE ) group by BG_TURNOVER, MARKET;
Which looks like:
BG_TURNOVER MARKET count
sports_returns_l90d_5000+ Romania 497864
sports_returns_l90d_1000_2500 Hungary 2986
sports_returns_l90d_0 Belgium Dutch 14103
sports_returns_l90d_5000+ Intl French 6745
...
However, I wanted to apply multiple columns in place of sports_returns_l90d. Then have the string match that column name.
For example:
select BG_TURNOVER, MARKET, count(*)
FROM( SELECT (CASE
WHEN X = 0
THEN 'X_0'
WHEN X > 0 AND X <= 500
THEN 'X_0_500'
WHEN X > 500 AND X <= 1000
THEN 'X_500_1000'
WHEN X > 1000 AND X <= 2500
THEN 'X_1000_2500'
WHEN X > 2500 AND X <= 5000
THEN 'X_2500_5000'
ELSE 'X_5000+'
END) AS BG_TURNOVER, MARKET
FROM PRODUCT_TABLE ) group by BG_TURNOVER, MARKET;
Whereby X takes the column names: sports_return_l90d, sports_returns, bingo_returns, is there a way to iterate over all of these?

Answer 1

If you have the sports_return_l90d, sports_returns, bingo_returns values in different columns such as:
CREATE TABLE product_table ( sports_return_l90d, sports_returns, bingo_returns, market ) AS
SELECT 1000, 5500, 1, 'AAA' FROM DUAL CONNECT BY LEVEL <= 10;
Then you can use:
SELECT type ||
CASE
WHEN bg_turnover = 0
THEN '_0'
WHEN bg_turnover > 0 AND bg_turnover <= 500
THEN '_0_500'
WHEN bg_turnover > 500 AND bg_turnover <= 1000
THEN '_500_1000'
WHEN bg_turnover > 1000 AND bg_turnover <= 2500
THEN '_1000_2500'
WHEN bg_turnover > 2500 AND bg_turnover <= 5000
THEN '_2500_5000'
ELSE '_5000+'
END AS BG_TURNOVER,
MARKET,
count(*)
FROM PRODUCT_TABLE
UNPIVOT (
bg_turnover FOR type IN (
sports_return_l90d AS 'sports_return_l90d',
sports_returns AS 'sports_returns',
bingo_returns AS 'bingo_returns'
)
)
GROUP BY
type,
CASE
WHEN bg_turnover = 0
THEN '_0'
WHEN bg_turnover > 0 AND bg_turnover <= 500
THEN '_0_500'
WHEN bg_turnover > 500 AND bg_turnover <= 1000
THEN '_500_1000'
WHEN bg_turnover > 1000 AND bg_turnover <= 2500
THEN '_1000_2500'
WHEN bg_turnover > 2500 AND bg_turnover <= 5000
THEN '_2500_5000'
ELSE '_5000+'
END,
MARKET;
Which outputs:
BG_TURNOVER
MARKET
COUNT(*)
sports_return_l90d_500_1000
AAA
10
sports_returns_5000+
AAA
10
bingo_returns_0_500
AAA
10
fiddle