请教进制数转换的函数

Question

SELECT BIN_TO_NUM(1,0,1,0) FROM DUAL; BIN_TO_NUM(1,0,1,0)
-------------------
                 10

Answer 1

http://expert.csdn.net/Expert/topic/1890/1890719.xml?temp=.3415949

Answer 2

create or replace function get2(aa int)
return varchar2
as
result varchar2(100);
temp int;
begin
temp:=aa;
result:=to_char(mod(temp,2))||result;
temp:=temp/2;
while temp>0 loop
  result:=to_char(mod(temp,2))||result;
  temp:=trunc(temp/2);
end loop;
return result;
end;
/
select get2(8) from dual;
/

Answer 3

create or replace function get2(aa int)
return varchar2
as
result varchar2(100);
temp int;
begin
temp:=aa;
result:=to_char(mod(temp,2))||result;
temp:=trunc(temp/2);
while temp>0 loop
  result:=to_char(mod(temp,2))||result;
  temp:=trunc(temp/2);
end loop;
return result;
end;
/
select get2(8) from dual;
/