How can we calculate cumulative payroll separately for each department?
Combining PARTITION BY with ORDER BY computes running totals that reset at each department boundary.
Department-level cumulative spending, regional quota tracking, isolated running metrics.
SELECT
department_id,
name,
salary,
SUM(salary) OVER (
PARTITION BY department_id
ORDER BY salary
) AS department_running_total
FROM employees;Practice typing production-grade SQL code for Partitioned Running Total.