Need sql query to get expected output for the below, - sql

Question

Tried the below query, but it works only for the first and second records.
Select
name,
dept,
sal,
(
coalesce(sal, 0) + coalesce(saltodrop)
) as running total (
SELECT
name,
dept,
sal,
LAG(Sal, 1, 0) OVER(
PARTITION BY [dept]
ORDER BY
[name],
[dept] ASC
) AS [saltodrop]
FROM
dataset
) as data_set_extract
Input
Name dept sal
John sales 10000
Tom sales 8000
Tim sales 5000
George finance 6000
Dane finance 4000
Mike hr 5000
Meme hr 6000
Ark it 5000
Output
Name dept sal
John sales 1000
Tom sales 18000
Tim sales 23000
George finance 29000
Dane finance 33000
Mike hr 38000
Meme hr 44000
Ark it 49000
Using the Oracle database, I need to add a consecutive row of the
first two records, later the sum of the first record and second record
with that of the third record and so on.

Answer 1

Assuming you have already ordered the results then use the SUM analytic function and order by ROWNUM to keep the current ordering:
SELECT t.*,
SUM(sal) OVER (ORDER BY ROWNUM) AS cumulative_sal
FROM table_name t;
Which, for the sample data:
CREATE TABLE table_name (Name, dept, sal) AS
SELECT 'John', 'sales', 10000 FROM DUAL UNION ALL
SELECT 'Tom', 'sales', 8000 FROM DUAL UNION ALL
SELECT 'Tim', 'sales', 5000 FROM DUAL UNION ALL
SELECT 'George', 'finance', 6000 FROM DUAL UNION ALL
SELECT 'Dane', 'finance', 4000 FROM DUAL UNION ALL
SELECT 'Mike', 'hr', 5000 FROM DUAL UNION ALL
SELECT 'Meme', 'hr', 6000 FROM DUAL UNION ALL
SELECT 'Ark', 'it', 5000 FROM DUAL;
Outputs:
NAME
DEPT
SAL
CUMULATIVE_SAL
John
sales
10000
10000
Tom
sales
8000
18000
Tim
sales
5000
23000
George
finance
6000
29000
Dane
finance
4000
33000
Mike
hr
5000
38000
Meme
hr
6000
44000
Ark
it
5000
49000
db<>fiddle here