How to divide two queries and then group by? - sql-server

Question

I need to divide two queries, but I need to save 'group by' categories. With my query I only get values and their cartesian product.
Select m2.regionname, m2.indicatorname CAST( m2.a2Value as float) /
m1.a1Value
from(
select r.name as regionname , ina.name as indicatorname, sum(a.value) as
a1Value
from Region as "r"
left join city_region as "cr" on r.region_id = cr.region_id
left join Office as "o" on cr.city_id = o.city_id
left join Assets as "a" on o.office_id = a.office_id
left join Indicators as "i" on a.indicator_id = i.indicator_id
left join IndicatorNames as "ina" on i.indicator_name_id =
ina.indicator__name_id
where a.month between '01-01-2019' and '31-01-2019'
group by r.name, ina.name
) m1 join (
select r.name as regionname , ina.name as indicatorname, sum(a.value) as
a2Value
from Region as "r"
left join city_region as "cr" on r.region_id = cr.region_id
left join Office as "o" on cr.city_id = o.city_id
left join Assets as "a" on o.office_id = a.office_id
left join Indicators as "i" on a.indicator_id = i.indicator_id
left join IndicatorNames as "ina" on i.indicator_name_id =
ina.indicator__name_id
where a.month between '01-02-2019' and '27-02-2019'
group by r.name, ina.name) m2 on m1.regionname = m2.regionname
I need to get 4 rows and 3 columns, that includes region_name, indicator_name and float value.
But I only cant get table with values
0,0482248520710059
0,0565972222222222
0,0665680473372781
0,078125
0,705627705627706
0,974025974025974
1,01875
1,03550295857988
1,18343195266272
1,21527777777778
1,38888888888889
1,40625
15,1515151515152
17,3160173160173
21,875
25
but that is wrong.

Answer 1

This condition in the ON clause:
on m1.regionname = m2.regionname
will join many unrelated rows.
You must set another condition like:
on m1.regionname = m2.regionname and m1.indicatorname = m2.indicatorname

Answer 2

try Something like this:
select *, case when a1Value=0 then null else cast(a2Value as float) / a1Value end Ratio
from (
select r.name as regionname , ina.name as indicatorname,
sum(case when a.month between '01-01-2019' and '31-01-2019' then a.value else 0 end) as a1Value,
sum(case when a.month between '01-02-2019' and '27-02-2019' then a.value else 0 end) as a2Value
from Region r
left join city_region cr on r.region_id = cr.region_id
left join Office o on cr.city_id = o.city_id
left join Assets a on o.office_id = a.office_id and a.month between '01-01-2019' and '27-02-2019'
left join Indicators i on a.indicator_id = i.indicator_id
left join IndicatorNames ina on i.indicator_name_id = ina.indicator__name_id
group by r.name, ina.name
) tmp