写出函数如何将123456789实现转置输出0987654321

create or replace function reverse_string(v_strings in varchar2) return varchar2 is

r varchar2(30):='';

va varchar2(30):='';

begin

for i in 1..length(v_strings) loop

va:=substr(v_strings,length(v_strings)+1-i,1);

r:=r||va;

end loop;

return r;

end;

declare

v varchar2(30):='';

begin

v:=reverse_string('1234567890');

dbms_output.put_line(v);

end;