OraclePL/SQL-based GROUPBYROLLUP

ROLLUP literally means to roll up the volume. It can be used in GROUPBY to accumulate the sum: If there is no ROLLUP, the following query is based on department_id and job _

ROLLUP literally means to roll to, used in group by can play a cumulative sum function: Without ROLLUP, the following query BY department_id and job _

ROLLUP literally means to roll to, used in group by can play a cumulative sum role:

If no ROLLUP exists, the following query sums the groups by department_id and job_id:

Output:

With ROLLUP:

Group and sum department_id and job_id, sum them according to department_id, and calculate the sum:

Output:

Group and sum the department_id and job_id, sum the sum according to job_id, and finally calculate the sum:

Output: