Calculate Running Total Amount with Bonus - sql

Question

I have following table:
create table test_table
(
employee_id integer,
salary_year integer,
raise_in_salary_perentage decimal(18,2),
annual_salary decimal(18,2)
);
**Test Data is following: **
insert into test_table values ( 1,2016, 0 , 100);
insert into test_table values ( 1,2017, 10, 100);
insert into test_table values ( 1,2018, 10, 100);
insert into test_table values ( 1,2019, 0, 100);
insert into test_table values ( 1,2020, 10, 100);
insert into test_table values ( 2,2016, 10 , 100);
insert into test_table values ( 2,2017, 10, 100);
insert into test_table values ( 2,2018, 0, 100);
insert into test_table values ( 2,2019, 0, 100);
insert into test_table values ( 2,2020, 0, 100);
I am trying to achieve following output:
The cumulative salary should include the running total of annual salary over years for each employee.
There is a percentage of raise every year, so if current year has a raise the cumulative salary will be sum of previous salaries plus the amount received in raise.
I tried to achieve it using following SQL, but results does seems right. Will be thankful for solution.
SELECT *
,sum(annual_salary) OVER (
PARTITION BY employee_id ORDER BY salary_year ROWS BETWEEN UNBOUNDED PRECEDING
AND CURRENT ROW
) AS cummulative_salary
,(
sum(annual_salary) OVER (
PARTITION BY employee_id ORDER BY salary_year ROWS BETWEEN UNBOUNDED PRECEDING
AND CURRENT ROW
)
) + (
sum(annual_salary) OVER (
PARTITION BY employee_id ORDER BY salary_year ROWS BETWEEN UNBOUNDED PRECEDING
AND CURRENT ROW
)
) * (
sum(raise_in_salary_perentage) OVER (
PARTITION BY employee_id ORDER BY salary_year ROWS BETWEEN UNBOUNDED PRECEDING
AND CURRENT ROW
) / 100
) AS csalary
FROM test_table;

Answer 1

Based on your description, the increase in salary should be cumulative. However, a given year's increase should not affect previous years.
That is not what your desired results show. Based on my interpretation, I think you want:
with recursive cte as (
select employee_id, salary_year, (t.annual_salary * (1 + raise_in_salary_perentage / 100.0))::numeric(18, 2) as annual_salary,
raise_in_salary_perentage,
(t.annual_salary * (1 + raise_in_salary_perentage / 100.0))::numeric(18, 2) as total
from test_table t
where salary_year = 2016
union all
select t.employee_id, t.salary_year, (cte.annual_salary * (1 + t.raise_in_salary_perentage / 100.0))::numeric(18, 2),
t.raise_in_salary_perentage,
(cte.total + cte.annual_salary * (1 + t.raise_in_salary_perentage / 100.0))::numeric(18, 2)
from cte join
test_table t
on t.employee_id = cte.employee_id and t.salary_year = cte.salary_year + 1
)
select *
from cte
order by employee_id, salary_year;
Here is a db<>fiddle.