An old thread but, yes... there is a way to do it in Oracle:

    with

    employee(id, firstname, lastname, hobbies) as
    (
      select 1, 'a', 'b', '1' from dual union 
      select 2, 'a', 'b', '2' from dual union 
      select 3, 'a', 'b', '3' from dual union 
      select 4, 'c', 'd', '3' from dual union 
      select 5, 'e', 'f', '2' from dual  
    )

    select * 
    from employee 
    pivot
    ( 
      max(1) fake  
      for (hobbies) -- put the undesired columns here
      IN () 
    ) 
    where 1=1 -- and anything more...
    order by id

What it does - the <b>PIVOT</b> - is group all rows through all columns except those declared in the <b>PIVOT</b> clause. The declared columns will be replaced by new columns defined by the aggregations before the <b>FOR</b> clause for each filter specified inside the <b>IN</b> clause. 

A better example would be the following query:

    select * 
    from employee 
    pivot
    (
      max(id) foo,
      max(1)  bar
      for (hobbies) 
      IN ('2' as two, '3' as three)
    )

That's the result: <br/>
<pre>
FIRSTNAME | LASTNAME | TWO_FOO | TWO_BAR | THREE_FOO | THREE_BAR
    c          d         null      null        4           1
    e          f           5        1         null        null
    a          b           2        1          3           1
</pre>

All columns except the <b>id</b> and <b>hobbies</b> will be grouped, so it will group by <b>firstname</b> and <b>lastname</b>, which will result in three groups ('c', 'd') | ('e', 'f') | ('a', 'b'). Following, four columns will be created... two aggregation columns (as there are two <b>MAX</b> clause specified) for each filter in the <b>IN</b> clause and the aggregations are applied in the resulting groups.

Well, returning to the first query, it does works for two reasons:<br/>
1- you will not lose any row in the grouping process because the <b>id</b> column is unique and no columns were specified for aggregations; <br/>
2- as the pivot generates N * M new columns, where N = "number of filters" and M = "number of aggregations", having no filters and that single "harmless" aggregation means in 1 * 0 = 0 new columns, also removing all columns specified in the <b>PIVOT</b> clause, which is just the <b>hobbies</b>.