Firebird 4.0

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select rdb$get_context('SYSTEM', 'ENGINE_VERSION') as version
     , rdb$character_set_name
from rdb$database;


VERSION
RDB$CHARACTER_SET_NAME


4.0.1
UTF8


create table events (
  event_date date not null,
  event_count integer not null
);
execute block as
begin
  insert into events (event_date, event_count) values (date '2022-04-01', 15);
  insert into events (event_date, event_count) values (date '2022-09-30', 10);
  insert into events (event_date, event_count) values (date '2022-10-01', 1);
  insert into events (event_date, event_count) values (date '2022-10-04', 1);
end
4 rows affected

select 
  event_date,
  event_count,
  event_count_running_total,
  datediff(day, event_date, current_date) days_ago
from (
  select 
    event_date, 
    event_count, 
    sum(event_count) over (order by event_date desc) event_count_running_total
  from events
)
where event_count_running_total >= 3
order by event_date desc
fetch first row only


EVENT_DATE
EVENT_COUNT
EVENT_COUNT_RUNNING_TOTAL
DAYS_AGO


2022-09-30
10
12
193


select 
  event_date,
  event_count,
  event_count_running_total,
  event_count_running_prev,
  datediff(day, event_date, current_date) days_ago
from (
  select 
    event_date, 
    event_count, 
    sum(event_count) over (order by event_date desc) event_count_running_total, 
    sum(event_count) over (order by event_date desc rows between unbounded preceding and 1 preceding) event_count_running_prev
  from events
)
where 3 between event_count_running_prev and event_count_running_total


EVENT_DATE
EVENT_COUNT
EVENT_COUNT_RUNNING_TOTAL
EVENT_COUNT_RUNNING_PREV
DAYS_AGO


2022-09-30
10
12
2
193