Ideas on how to best flatten a structure

Question

Hello,
I need to take the data in a table and flatten it. e.g.
The data is stored like this:
Id Description
1 Cat
2 Dog
3 Bird
4 Tree
I have to make a table with the "Description" elements as columns. i.e. the final table would have the following columns:
Cat Dog Bird Tree ...
The number of columns is not fixed, it will be based on how many rows are in the original table.
I can think of a few pretty rough ways of doing it. i.e. Using Unix Shell/SQL to generate a create table script i.e.
CREATE TABLE descriptions
( cat VARCHAR2(100),
bird VARCHAR2(100)
etc);
Is there any way I can do this in straight PLSQL? can I write dynamic DDL (I assume I can?). Or is there an even more powerful/elegant way of flattening a table in the manner in Oracle 9i??
Thanks,
Dan.
[email protected]

Answer 1

Tom Kytes has some examples of pivot queries to do this sort of thing, but I don't believe he's extended them to handle an arbitrary number of columns. You should be able to turn Tom's statis SQL queries into dynamic SQL queries, though, which would get you to your arbitrary columns requirement.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC