DM中提供BIN_TO_NUM函数，可以将二进制转换成十进制数。示例如下：
SELECT BIN_TO_NUM(1, 1, 0, 1,1,0,1) FROM DUAL;

自定义一个函数吧。

bin_to_num参数可能要在达梦最新版本才支持，另外书写参数也麻烦。

CREATE OR REPLACE FUNCTION binary_to_num (pbin VARCHAR2) 
RETURN BIGINT DETERMINISTIC
IS  
   v_len   INT := LENGTH (pbin);  
   v_num   BIGINT := 0;  
BEGIN  
   FOR i IN 1..v_len LOOP  
      IF SUBSTR(pbin, i, 1) = '1' THEN  
         v_num := v_num + POWER(2, v_len - i);  
      END IF;  
   END LOOP;  
  
   RETURN v_num;  
END binary_to_num;  
/  

试着写了个进制间转换的小函数，你测试下，看看是否与mysql里的conv函数功能接近

F_CONV.sql

--测试脚本
SELECT F_CONV('101011010110010100110100010',2,10) AS BIN2DEC
      ,F_CONV('90909090',10,16)                   AS DEC2HEX
      ,F_CONV('56B29A2',16,8)                     AS HEX2OCT
      ,F_CONV('532624642',8,2)                    AS OCT2BIN
      ,F_CONV('56B29A2',16,93)                    AS HEX2B93
      ,F_CONV('1K1_9',93,6)                       AS B932B6
      ,F_CONV('13004255230',6,36)                 AS B62B36
      ,F_CONV('1I4HWI',36,10)                     AS B362DEC
;
--输出结果
BIN2DEC	90909090
DEC2HEX	56B29A2
HEX2OCT	532624642
OCT2BIN	101011010110010100110100010
HEX2B93	1K1_9
B932B6	13004255230
B62B36	1I4HWI
B362DEC	90909090