MySQL 8.0

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select version();


version()


8.0.30


create table a (date date, amount int, b_id int);
insert into a (date, amount, b_id) values
  ('1900-01-01', 10000, 1),
  ('2020-01-01', 3000000, 1),
  ('2019-08-01', 15012, 1),
  ('2019-06-21', 90909, 1),
  ('2020-01-15', 84562, 1);

Records: 5  Duplicates: 0  Warnings: 0


create table b (id int, type int);
insert into b (id, type) values (1, 7), (2, 5);

Records: 2  Duplicates: 0  Warnings: 0


with months (date) as
(
  select last_day(current_date - interval  1 month) union all
  select last_day(current_date - interval  2 month) union all
  select last_day(current_date - interval  3 month) union all
  select last_day(current_date - interval  4 month) union all
  select last_day(current_date - interval  5 month) union all
  select last_day(current_date - interval  6 month) union all
  select last_day(current_date - interval  7 month) union all
  select last_day(current_date - interval  8 month) union all
  select last_day(current_date - interval  9 month) union all
  select last_day(current_date - interval 10 month) union all
  select last_day(current_date - interval 11 month) union all
  select last_day(current_date - interval 12 month)
)
, data (date, amount, type) as
(
  select last_day(a.date), a.amount, b.type
  from a
  join b on b.id = a.b_id
  where type in (5, 7)
  union all
  select date, null, null from months
)
select
  date,
  sum(sum(case when type = 5 then amount end)) over (order by date) as t5,
  sum(sum(case when type = 7 then amount end)) over (order by date) as t7
from data
group by date
order by date
limit 12;


date
t5
t7


1900-01-31
null
10000

2019-06-30
null
100909

2019-08-31
null
115921

2020-01-31
null
3200483

2023-01-31
null
3200483

2023-02-28
null
3200483

2023-03-31
null
3200483

2023-04-30
null
3200483

2023-05-31
null
3200483

2023-06-30
null
3200483

2023-07-31
null
3200483

2023-08-31
null
3200483

date	t5	t7
1900-01-31	null	10000
2019-06-30	null	100909
2019-08-31	null	115921
2020-01-31	null	3200483
2023-01-31	null	3200483
2023-02-28	null	3200483
2023-03-31	null	3200483
2023-04-30	null	3200483
2023-05-31	null	3200483
2023-06-30	null	3200483
2023-07-31	null	3200483
2023-08-31	null	3200483