Generic Dump Nested Collection Procedure?

Question

Greetings,
Anyone have a proc which when passed a (possibly deeply) nested collection will dump a pretty-printed representation via dbms_output?
I know this is a mostly just a typing exercise using recursion, but
1. my PL/SQL skills apparently aren't up to the task
2. I don't see any kind of get_type() function for the dump proc to use to decide how to loop through sub-collections
so I'd like to see how the experts do it.
Am using 10g.
Thanks,
--jim
example:
DECLARE
  TYPE numset_t IS TABLE OF NUMBER;
  TYPE numset_t_aa IS TABLE OF numset_t INDEX BY VARCHAR2(16);
  TYPE numset_t_aa_v IS VARRAY(2) OF numset_t_aa;
  n_aa numset_t_aa;
  n_t_aa_v numset_t_aa_v;
BEGIN
  n_aa('tens') := numset_t(10,11,12);
  n_aa('ones') := numset_t(1,2,3);
  n_t_aa_v(1) := n_aa;
  n_aa.DELETE('ones');
  SELECT * BULK COLLECT INTO n_aa('hundreds') FROM table(numset_t(103,102,101));
  n_t_aa_v(2) := n_aa;
  dbms_output('dumping n_t_aa_v:');
  dump_collection(n_t_aa_v);
END;expected output:
dumping dumping n_t_aa_v:
1:
  tens:
    1: 10
    2: 11
    3: 12
  ones:
    1: 1
    2: 2
    3: 3
2:
  tens:
    1: 10
    2: 11
    3: 12
  hundreds:
    1: 103
    2: 102
    3: 101

Answer 1

Hi,
Why are you using collections in the first place?
If the sole purpose here is to generate XML, then you don't need collection at all, just query your base tables with SQL/XML functions.
If these collections are part of a larger process (besides generating XML), then you'll need to use at least SQL types instead of local PL/SQL types if you want to efficiently generate XML out of them.
For example, using the XMLType constructor over the topmost object : {message:id=10012696}