如: type tab is table of number index by varchar2(50); t1 tab; t1('a') := 100; t1('b') := 200; t1('c') := 50; t1('d') := 600; 怎么根据值排序,降序排序,600/200/100/50
类型转换的问题,这样。
select *
from (select '600' a
from dual
union all
select '200'
from dual
union all
select '100'
from dual
union all
select '50'
from dual) t
order by to_number(a) desc