Rewrite the query to get output for cross years? - sql

Question

SELECT
sum(case
when "year" = '2016' then "svalue"
ELSE 0
END) as 'sva_2016',
sum(case
when "year" = '2017' then "svalue"
ELSE 0
END) as 'sva_2017',
sum(case
when "year" = '2018' then "svalue"
ELSE 0
END) as 'sva_2018',
sum(case
when "year" = '2019' then "svalue"
ELSE 0
END) as 'sva_2019',
sum(case
when "year" = '2016' then "ltr"
ELSE 0
END) as 'lva_2016',
sum(case
when "year" = '2017' then "ltr"
ELSE 0
END) as 'lva_2017',
sum(case
when "year" = '2018' then "ltr"
ELSE 0
END) as 'lva_2018',
sum(case
when "year" = '2019' then "ltr"
ELSE 0
END) as 'lva_2019',
'Apr 1 - Jan 31' as 'Period',
"code" as 'FACode'
FROM "FCJOIN"
WHERE "code" IN
(
SELECT "fccode"
FROM "fcdetails"
)
AND "month" between '04' and '12'
AND "year" IN ( '2016' , '2017' , '2018' , '2019' )
GROUP BY "code"
The above query gives me the correct out put for svalues and ltr for
April 2016- December 2016
April 2017- December 2017
April 2018- December 2018
April 2019- December 2019
Now I want to get the values of svalues and ltrs for the period of
April 2016- January 2017
April 2017- January 2018
April 2018- January 2019
April 2019- January 2020

Answer 1

You may use CAST("year" + '-' + "month" + '-01' AS DATETIME) to compare operations.
Btw. it is good example to use PIVOT operator.

Answer 2

Convert the year/month to a date and use date comparisons:
select f.code,
sum(case when v.dte >= '2016-04-01' and v.dte < '2017-04-01'
then f.svalue else 0
end) as svalue_2016,
. . .
sum(case when v.dte >= '2016-04-01' and v.dte < '2017-04-01'
then f.ltr else 0
end) as ltr_2016,
. . .
from fcjoin f cross apply
(values (datefromparts(f.year, f.month, 1))
) v(dte)
where f.code in (select fd.fccode from fcdetails fd)
group by code;
I removed all the double quotes, because they just complicate the query.