I'm writing a query which result will be displayed as dashboard on redash. The query is basically a sum of several columns of table within a specific time range:
SELECT
sum(col_A),
sum(col_B),
sum(col_C)
FROM
table_X
WHERE
timestamp > '2018-01-01'
AND timestamp < '2018-02-01'
The result is something like this:
col_A col_B col_C
123 456 789
However, to render the dasboard on redash properly, I need the result in long format:
column sum
col_A 123
col_B 456
col_C 789
How can I cast the result from wide to long format?