Join two tables to one recordset with nested table?

Question

Hello all!
I want to "de-normalize" two tables into one for presentation reasons. For example:
CREATE TABLE foo(id number)
CREATE TABLE bar(foo_id number, value varchar2(4))
And with some data:
FOO:
1
2
BAR:
1, 'gaz'
1, 'boz'
2, 'blah'
Now I want to create a view that holds the value of the BAR table in a nested table, if possible and efficient enough..
VIEW:
1, nested_table('gaz,'boz')
2, nested_table('blah')
Any clue for creating such a view? I would prefer a view, because this view will be joined with other tables later.
Thanks in advice!

Answer 1

Or
SQL> with foo as
  2  ( select 1 id from dual union all
  3    select 2 id from dual
  4  ),
  5  bar as
  6  (
  7    select 1 foo_id, 'gaz'  value from dual union all
  8    select 1 foo_id, 'boz'  value from dual union all
  9    select 2 foo_id, 'blah' value from dual
10  )
11  --
12  --
13  select id,
14         cast(multiset((select value from bar where id=foo_id)) as sys.dbms_debug_vc2coll) value
15    from foo
16  /
        ID VALUE
         1 DBMS_DEBUG_VC2COLL('gaz', 'boz')
         2 DBMS_DEBUG_VC2COLL('blah')or from 10g on
SQL> with foo as
  2  ( select 1 id from dual union all
  3    select 2 id from dual
  4  ),
  5  bar as
  6  (
  7    select 1 foo_id, 'gaz'  value from dual union all
  8    select 1 foo_id, 'boz'  value from dual union all
  9    select 2 foo_id, 'blah' value from dual
10  )
11  --
12  --
13  select id,
14         cast(collect(value) as sys.dbms_debug_vc2coll) value
15    from foo, bar
16    where id=foo_id
17    group by id
18  /
        ID VALUE
         1 DBMS_DEBUG_VC2COLL('gaz', 'boz')
         2 DBMS_DEBUG_VC2COLL('blah')Edited by: michaels2 on Oct 8, 2008 2:27 PM