怎样实现ORACLE中用一条SQL实现其它进制到十进制的转换？
-----二进制转换十进制-----------------
select sum(data1)
  from (select substr('1101', rownum, 1) * power
(2, length('1101') - rownum) data1
          from dual
        connect by rownum <= length('1101'))

-----八进制转换十进制-----------------
select sum(data1)
  from (select substr('1101', rownum, 1) * power
(8, length('1101') - rownum) data1
          from dual
        connect by rownum <= length('1101'))

-----十六进制转换十进制-----------------
select sum(data1)
  from (select (CASE upper(substr('2D', rownum, 1))
                 WHEN 'A' THEN '10'
                 WHEN 'B' THEN '11'
                 WHEN 'C' THEN '12'
                 WHEN 'D' THEN '13'
                 WHEN 'E' THEN '14'
                 WHEN 'F' THEN '15'
                 ELSE substr('2D', rownum, 1)
               END) * power(16, length('2D') - rownum) data1
          from dual
        connect by rownum <= length('2D'))
 

注：

对其它进制可以根据例子将power的底数改成相应的进制就可以了。

本文只是一个例子，大家可以把它封装成一个通用函数进行实用。