Select query payment schedule - sql

Question

There is a table on the payment schedule:
| PaySum | PlanDate |
+----------+------------+
| 23928.38 | 14.10.2019 |
| 24347.13 | 12.11.2019 |
| 24773.20 | 12.12.2020 |
| 25206.73 | 13.01.2020 |
Need to pull forthcoming amount for 3 months
My request for example:
select sum(s.PaySum)
from L_DEA s
where s.PlanDate between trunc(sysdate + 1) and
ADD_months(trunc(sysdate + 1), 3)
and ID = :iId;
This query returns 4 months if run sysdate = 12.10.19 or 13.10.19
in other cases shows correctly for 3 months
How to form select correctly

Answer 1

Perhaps try changing the inequality:
SELECT SUM(s.PaySum)
FROM L_DEA s
WHERE
s.PlanDate >= TRUNC(SYSDATE) AND
s.PlanDate < ADD_MONTHS(TRUNC(SYSDATE + 1), 3) AND
ID = :iId;
This would include all plan dates on or after midnight of today, but before midnight of three months from now.

Answer 2

I don't agree with you. At least in the given sample data, It is working correctly.
For 12-Oct-2019
SQL> with L_DEA (PaySum, PlanDate) as
2 (select 23928.38 , to_date('14.10.2019','dd.mm.yyyy') from dual union all
3 select 24347.13 , to_date('12.11.2019','dd.mm.yyyy') from dual union all
4 select 24773.20 , to_date('12.12.2020','dd.mm.yyyy') from dual union all
5 select 24773.20 , to_date('10.02.2020','dd.mm.yyyy') from dual union all -- added this
6 select 25206.73 , to_date('13.01.2020','dd.mm.yyyy') from dual )
7 select * --sum(s.PaySum)
8 from L_DEA s
9 where s.PlanDate between trunc(date '2019-10-12' + 1) and
10 ADD_months(trunc(date '2019-10-12' + 1), 3)
11 --and ID = :iId;
PAYSUM PLANDATE
---------- ---------
23928.38 14-OCT-19
24347.13 12-NOV-19
25206.73 13-JAN-20
SQL>
for another date i.e. 13-Oct-2019
SQL> with L_DEA (PaySum, PlanDate) as
2 (select 23928.38 , to_date('14.10.2019','dd.mm.yyyy') from dual union all
3 select 24347.13 , to_date('12.11.2019','dd.mm.yyyy') from dual union all
4 select 24773.20 , to_date('12.12.2020','dd.mm.yyyy') from dual union all
5 select 24773.20 , to_date('10.02.2020','dd.mm.yyyy') from dual union all -- added this
6 select 25206.73 , to_date('13.01.2020','dd.mm.yyyy') from dual )
7 select * --sum(s.PaySum)
8 from L_DEA s
9 where s.PlanDate between trunc(date '2019-10-13' + 1) and
10 ADD_months(trunc(date '2019-10-13' + 1), 3)
11 --and ID = :iId;
PAYSUM PLANDATE
---------- ---------
23928.38 14-OCT-19
24347.13 12-NOV-19
25206.73 13-JAN-20
SQL>
Cheers!!

Answer 3

One abbreviate option to cover the period starting from the present day to three months later would be :
select sum(s.PaySum)
from l_dea s
where s.PlanDate between trunc(systimestamp) and trunc(systimestamp) + interval '3' month
and ID = :iId

Answer 4

select s.PlanDate, s.PaySum
from L_DEA s
inner join (select PlanDate
from (select distinct s.PlanDate
from L_DEA s
where ID = :iId
and s.PlanDate >= (to_date('10.10.2019'))
order by s.PlanDate) tt
where rownum <= 3) A2
on s.PlanDate = A2.PlanDate
where ID = :iId);