2018.02.14
Hex to decimal
目次
Hex to decimalについて
次のスクリプトは、16進数/8進数/2進数/10進数の間で変換をしてくれる関数としてTom Ktye
によって作成された。
create or replace function to_base( p_dec in number, p_base in number ) return varchar2 is l_str varchar2(255) default NULL; l_num number default p_dec; l_hex varchar2(16) default '0123456789ABCDEF'; begin if ( trunc(p_dec) <> p_dec OR p_dec < 0 ) then raise PROGRAM_ERROR; end if; loop l_str := substr( l_hex, mod(l_num,p_base)+1, 1 ) || l_str; l_num := trunc( l_num/p_base ); exit when ( l_num = 0 ); end loop; return l_str; end to_base; / create or replace function to_dec ( p_str in varchar2, p_from_base in number default 16 ) return number is l_num number default 0; l_hex varchar2(16) default '0123456789ABCDEF'; begin for i in 1 .. length(p_str) loop l_num := l_num * p_from_base + instr(l_hex,upper(substr(p_str,i,1)))-1; end loop; return l_num; end to_dec; / show errors create or replace function to_hex( p_dec in number ) return varchar2 is begin return to_base( p_dec, 16 ); end to_hex; / create or replace function to_bin( p_dec in number ) return varchar2 is begin return to_base( p_dec, 2 ); end to_bin; / create or replace function to_oct( p_dec in number ) return varchar2 is begin return to_base( p_dec, 8 ); end to_oct; /
使用例は以下の通りです。
SQL> select to_bin( 123 ) bin, to_hex( 123 ) hex, to_oct( 123 ) oct from dual 2 / BIN HEX OCT --------------- --------------- --------------- 1111011 7B 173 SQL> SQL> select to_dec( '1111011', 2 ) base2, to_dec( '7B' ) base16, 2 to_dec('173',8) base8 3 from dual 4 / BASE2 BASE16 BASE8 ---------- ---------- ---------- 123 123 123 If it is just hex you are after, then 8i also comes with a conversion format mask: SQL> select to_char(123123123,'xxxxxxxx') from dual; TO_CHAR(1 --------- 756b5b3