Nesting nested table

Question

Can a nested table Tab1 have another nested table Tab2 as an attribute? If yes, when the declaration of storing (e.g., nested table Tab2 store as Tab2_TAB) goes, in nested table Tab1 declaration (create type Tab1 as table of ...) or in Create table X that used double nested tables? THANKS for whoever can help me that!!!!! Elka

Answer 1

Multi-level nesting is only available since 9i. Before that, you'd need to break out the nesting as references to other object tables. Which is still a viable option depending on the business rules of your system. You're code was basically right, I just added an object table of type d_t with the syntax to provide storage for all the nested tables and ran a test insert to make sure you could get data in. Works fine. If you select * from that new table you'll see everything, but you may want to de-nest to only get specific data so you'll need to use the table function in your select statement. The oracle docs for all of this are quite good in the 'Application Developer's Guide - Object-Relational Features'. Check it out, and good luck!
Jason Ladd
E-Tech Solutions
create type a_t as object (
foobar varchar(20)
create type a_list_t as table of a_t
create type b_t as object (
foo_b varchar2(20),
foo_b_list a_list_t
create type b_list_t as table of b_t
create type c_t as object (
foo_c varchar2(20),
foo_c_list b_list_t
create type c_list_t as table of c_t
create type d_t as object (
foo_d varchar2(20),
foo_d_list c_list_t
create table d_table of d_t
nested table foo_d_list store as d_ntab1
(nested table foo_c_list store as d_ntab2
(nested table foo_b_list store as d_ntab3
insert into d_table values(
'foo_d',
(c_list_t(c_t('foo_c',(b_list_t(b_t('foo_b',(a_list_t(a_t('foobar')))))))))