实现IP地址与数值之间的转换

create or replace function ip2number(ip varchar2)
return number
is
ip_num_hex varchar2(80);
begin
if (regexp_like(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$')) then
ip_num_hex := lpad(trim(to_char(regexp_replace(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$', '/1'), 'XX')),2,'0') ||
lpad(trim(to_char(regexp_replace(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$', '/2'), 'XX')),2,'0') ||
lpad(trim(to_char(regexp_replace(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$', '/3'), 'XX')),2,'0') ||
lpad(trim(to_char(regexp_replace(ip, '^(/d{1,3})/.(/d{1,3})/.(/d{1,3})/.(/d{1,3})$', '/4'), 'XX')),2,'0');

return to_number(ip_num_hex, 'XXXXXXXX');
else
return -1;
end if;
exception
when others then
return -99999999999;
end;

select ip2number('169.254.55.6') from dual;

IP2NUMBER('169.254.55.6')
-------------------------
2852009734

create or replace function number2ip(num number)
return varchar2 is
ip_num_hex varchar2(8);
begin
ip_num_hex := lpad(trim(to_char(num, 'XXXXXXXX')), 8, '0');
return to_number(substr(ip_num_hex, 1, 2), 'XX') || '.' ||
to_number(substr(ip_num_hex, 3, 2), 'XX') || '.' ||
to_number(substr(ip_num_hex, 5, 2), 'XX') || '.' ||
to_number(substr(ip_num_hex, 7, 2), 'XX');
exception
when others then
dbms_output.put_line(sqlerrm);
return null;
end;

select number2ip(2852009734) from dual;

NUMBER2IP(2852009734)
--------------------------------------------------------------------------------
169.254.55.6