Mysql中实现提取字符串中的数字的自定义函数分享

CREATE FUNCTION GetNum (Varstring varchar(50))
RETURNS varchar(30)
BEGIN
DECLARE v_length INT DEFAULT 0;
DECLARE v_Tmp varchar(50) default '';
set v_length=CHAR_LENGTH(Varstring);
WHILE v_length > 0 DO

IF (ASCII(mid(Varstring,v_length,1))>47 and ASCII(mid(Varstring,v_length,1))<58 )   THEN
set v_Tmp=concat(v_Tmp,mid(Varstring,v_length,1));
END IF;
SET v_length = v_length - 1;
END WHILE;
RETURN REVERSE(v_Tmp);
END;

select GetNum(字段)  from table

select GetNum("dfdfd666")

select GetNum("dfdd111fd666")