select 'alter user "'||d.username||'" identified by values '''||u.password||''';' c
from dba_users d, sys.user$ u
where d.username = upper('&&username')
and u.user# = d.user_id;
source:
select 'alter user "'||d.username||'" identified by values '''||u.password||''';' c
from dba_users d, sys.user$ u
where d.username = upper('&&username')
and u.user# = d.user_id;