如何在SQL CASE表达式中返回多个值

Oracle数据库开发中CASE...THEN子句有时需要返回多个值用于判断，如何做才能在CASE...THEN表达式中返回多个值呢，具体参考下面的演示：

SQL> select case
  2           when to_char(sysdate, 'SS') > 30 then sys.odcivarchar2list('Sent')
  3           else sys.odcivarchar2list('New', 'Sent')
  4         end options
  5    from dual;

OPTIONS
--------------------------------------------------------------------------------
ODCIVARCHAR2LIST('Sent')

SQL> /

OPTIONS
--------------------------------------------------------------------------------
ODCIVARCHAR2LIST('New', 'Sent')

SQL> select *
  2    from table(
  3            select case when to_char(sysdate,'SS') > 30 then sys.odcivarchar2list('Sent')
  4                        else sys.odcivarchar2list('New','Sent')    
  5                   end options
  6            from dual
  7              );

COLUMN_VALUE
--------------------------------------------------------------------------------
New
Sent
SQL> /

COLUMN_VALUE
--------------------------------------------------------------------------------
Sent

SQL> select *
from emp
where report_status in 
(
select *
from table(
select
case
when to_char(sysdate,'SS') > 30 then sys.odcivarchar2list('Sent')
else sys.odcivarchar2list('New','Sent')
end options
from dual
)
) ;