Oracle 8i SQL Query

Question

I have a table with a hierarchy of business types. A business can be a sub business of another business if the parent's id is in the column PARENT_ID for a particular business. For example:
ID BUSINESS PARENT_ID
1 Top level NULL
2 Second Level 1 1
3 Second Level 2 1
4 Third Level 1 2
Now there is also another table with programs that relates to the business table. For example
PROGRAM PARENT_ID
Program 1 2
Program 2 4
which means that Program 1 belongs to the business Second Level 1 and Program 2 belongs to Third Level 1 but also belongs to Second Level 1 because Third Level 1 is a sub business of Second Level 1.
Basically, what I need to do is specify a business and get all of the programs that belong to that business and all of its sub-businesses. How would I build a query to get that? It is an Oracle 8i database that I am remotely accessing via ODBC. Thanks for any help.
Mark

Answer 1

Something like this ?
SQL> select * from business;
        ID NAME                  PARENT_ID
         1 Top level
         2 Second Level 1                1
         3 Second Level 2                1
         4 Third Level 1                 2
SQL> select * from program;
NAME        PARENT_ID
Program 1           2
Program 2           4
SQL> select p.name
  2  from PROGRAM p,
  3  (select id from BUSINESS
  4   start with id = 1
  5   connect by prior id = parent_id) b
  6  where b.id = p.parent_id
  7  /
NAME
Program 1
Program 2
SQL> select p.name
  2  from PROGRAM p,
  3  (select id from BUSINESS
  4   start with id = 2
  5   connect by prior id = parent_id) b
  6  where b.id = p.parent_id
  7  /
NAME
Program 1
Program 2
SQL> select p.name
  2  from PROGRAM p,
  3  (select id from BUSINESS
  4   start with id = 3
  5   connect by prior id = parent_id) b
  6  where b.id = p.parent_id
  7  /
no rows selected
SQL> select p.name
  2  from PROGRAM p,
  3  (select id from BUSINESS
  4   start with id = 4
  5   connect by prior id = parent_id) b
  6  where b.id = p.parent_id
  7  /
NAME
Program 2Rgds.