/* SCD - Slowly Changing Dimension - Type 2 - Course dimension       */ 
/* Department for JavaScript changed - New row is added when changed */

select * from course;


/* Display total instructor payment by course description */

select c.description, sum(gross_pay) 
from payment join course c using (course_id)
group by description with rollup;


/* Display total instructor payment by department */

select department, sum(gross_pay)
from payment join course using (course_id)
group by department with rollup;


/* Display total instructor payment by course and department */
/* Notice output has 2 JavaScript records */ 

select department, c.description, format(sum(gross_pay),2) as "gross pay" 
from payment join course c using (course_id)
group by department, c.description with rollup;