Big bits – really long bit strings

Posted by

A while back we had an AskTom question about arbitrary length addition and subtraction, and so I whipped a small PL./SQL in this post. A similar question came in recently about converting decimals to binary, but once again for decimals of arbitrary length.

So here’s a quick piece of PL/SQL for anyone wanting really a large number of bits Smile



SQL> create or replace
  2  function dec_to_bit(p_decimal varchar2) return varchar2 is
  3
  4    l_num varchar2(4000) := p_decimal;
  5    l_res varchar2(4000);
  6    l_last_dig pls_integer;
  7
  8    function div2(p_dec varchar2) return varchar2 is
  9      type   integer_array is  table of integer;
 10      n1     integer_array := integer_array();
 11      res    integer_array := integer_array();
 12      carry  pls_integer := 0;
 13      tmp    pls_integer;
 14      str    varchar2(1000);
 15    begin
 16      for i in 1 .. length(p_dec) loop
 17        n1.extend;
 18        n1(i) := to_number(substr(p_dec,i,1));
 19      end loop;
 20      res.extend(n1.count);
 21
 22      for i in 1 .. n1.count
 23      loop
 24         str := str || trunc(((10*carry)+n1(i))/2);
 25         carry := mod(n1(i),2);
 26      end loop;
 27      return ltrim(str,'0');
 28    end;
 29  begin
 30    loop
 31       l_last_dig := to_number(substr(l_num,-1,1));
 32       l_res := to_char(mod(l_last_dig,2)) || l_res;
 33       l_num := div2(l_num);
 34       exit when l_num is null;
 35    end loop;
 36    return l_res;
 37  end;
 38  /

Function created.

SQL>
SQL> set serverout on
SQL> select dec_to_bit('12321231231098371928379182739182734589729384752345') bitstr from dual;

BITSTR
----------------------------------------------------------------------------------------------------------------------------------
1000011011100011011100011101111011000101010000000100000110010110101110100110110011011010000101111010101100100110010010001000110001
0000011010100110001110010011011001

Enjoy!

Got some thoughts? Leave a comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.