string concatenation via Group By

Is it possible to concatenate records in a field via Group By clause of an SQL statement?

Untested script is :
create table t1(country varchar2(32), state varchar2(32), city varchar2 (32)) ;

insert into t1 values ('USA', 'CA', 'Sacramento') ;
insert into t1 values ('USA', 'CA', 'San Jose') ;
insert into t1 values ('USA', 'CA', 'three') ;
insert into t1 values ('USA', 'CA', 'four') ;
insert into t1 values ('USA', 'CA', 'Fremont') ;
insert into t1 values ('Canada', 'OT', 'Ottawa') ;
insert into t1 values ('Canada', 'OT', 'Toronto') ;

Expected output for the SQL statement would be :
USA   CA       Sacramento, San Jose, three, four, Fremont

Thanks in advance. Received on Tue Jan 26 2010 - 10:07:44 CST