DELETE HIERARCHY DATA,CONNECT BY SQL/PLSQ

Question

Hi
Please help with the logic!
I am trying to delete the data from the hierarchy table data(TABLE1) based on another table(TABLE2),For this i am using 2 cursors (get_ssn and get_max),
problem is with deleting the hierarchy data, there are several levels (few of them upto 10 levels), i have to delete from top to bottom level of the hierarchy structure
the first cursor returns the hierarchy structure
level ssn report_to baid
1
2
3
1
2
1
2
3
4
my plan is to pull the max of the level and delete it, loop the max value and decrement it by 1 in every iteration and delete the rows, below is the rough logic,
please help me building up the logic
declare
lev eweb.level%TYPE;
i = number :=0;
cursor get_ssn is --> this cursor is getting ssn based on simple join between two tables
select level, ssn, report_to, baid
from TABLE1
where ssn not in ( select e.ssn
from TABLE1 e, TABLE2 s
where e.ssn = s.ssn)
start with ssn in (select e.ssn
from TABLE1 e)
connect by prior report_to=baid;
cursor get_max is --> pulling the max of level
select max(level)
from eweb
where ssn not in ( select e.ssn
from TABLE1 e, TABLE2 s
where e.ssn = s.ssn)
start with ssn in (select e.ssn
from TABLE1 e)
connect by prior report_to=baid;
BEGIN
for i in get_ssn
loop i := i+1;
Delete from eweb --> here im trying to delete rows by using max(level)-i, in 1st iteration it takes the max value, in next iteration it will be max -1..........
where level = get_max-i
END LOOP;
end for loop;
END;
Edited by: user8884944 on Jun 23, 2010 11:34 AM

Answer 1

A few remarks
1 The subject line was shouted by using all caps. This must be considered rude
2 The introduction discusses 2 tables, yet the code deals with 3, and only from the third table data is deleted
3 no CREATE TABLE statements were posted, nor sample data
4 if you can put a constraint on the affected column, using on cascade delete, everything will be deleted automagically.
With this little information, no help is possible. We can not see what each statement does, the comments don't tell anything, and we can also not see what it is expected to do in terms of logics, as the statements are almost certainly wrong.
Sybrand Bakker
Senior Oracle DBA