/* Create a accumulation column, perform a nested subquery */
/* This is an example where the subquery is part of the SELECT list */


select vendor, description, pay_date, amount,

    (select sum(amount)
     from payment i
     where i.pay_date <= o.pay_date
     and MONTH(pay_date) = 3) as cumulative_amount      --for Oracle use
                                                        --TO_CHAR(pay_date,'MM') 
from  payment o
order by pay_date;



/* Create a accumulation column, perform a nested subquery */
/* This is an example where the subquery is part of the SELECT list */


SELECT course_id, description, price, 
(
    SELECT SUM(price) 
    FROM   course  i
    WHERE  i.course_id <= o.course_id       /*join inner to outer table*/               
    AND    i.course_id  > 'X52-9267'        /*other inner conditions   */
) 
AS accum_price 

FROM  course  o
/*WHERE o.course_id > 'X52-9267'*/          /*other outer conditions*/      
ORDER BY o.course_id;