Cartesian product (sum function on 2 tables)

Question

Dear all,
I have 2 tables with columns student_no (foreign key), date and amount in both tables.
now I want to select the sum of the amount for a student for specific date.
the following query is from stu_fee_payment table.
select sum(sfp.amount)
from stu_fee_payment sfp
where student_no =1
and sfp.pay_date < TO_DATE('01-AUG-2010','DD-MON-YYYY')
result: 200
the following query is from stu_fee_adjustment table.
select sum(sfa.adj_amount)
from stu_fee_adjustment sfa
where student_no =1
and sfa.adj_date < TO_DATE('01-AUG-2010','DD-MON-YYYY')
result: 400
now I have the following query
select sum(sfp.amount), sum(sfa.adj_amount)
from stu_fee_payment sfp, stu_fee_adjustment sfa
where sfp.student_no = sfa.student_no
and sfp.student_no =1
and sfp.pay_date < TO_DATE('01-AUG-2010','DD-MON-YYYY')
and sfa.adj_date < TO_DATE('01-AUG-2010','DD-MON-YYYY')
result: 400 400
its some kind of cartesian product because the two tables have no primary foreign key relationship.
how to solve the problem?
Regards:
MN
Edited by: Muhammad Nadeem on Aug 22, 2010 11:55 PM
Edited by: Muhammad Nadeem on Aug 23, 2010 12:58 AM

Answer 1

Hi Nadeem,
Try this one
SELECT sfp_sno,sfp_amount,sfa_amount
FROM
SELECT sfp.student_no sfp_sno, SUM(sfp.amount) sfp_amount
FROM stu_fee_payment sfp
WHERE sfp.pay_date < TO_DATE('01-AUG-2010','DD-MON-YYYY')
GROUP BY sfp.student_no
) x,
SELECT sfa.student_no sfa_sno, SUM(sfa.adj_amount) sfa_amount
FROM stu_fee_adjustment sfa
WHERE sfa.adj_date < TO_DATE('01-AUG-2010','DD-MON-YYYY')
GROUP BY sfa.student_no
)y
WHERE sfp_sno = sfp_no(+) Regards,
Sreekanth Munagala.