sql和C#10进制转化62进制

--@num 要转换的10进制
--@len 转换后保留支付长度
CREATE function [dbo].[intto62](@num bigint)
 returns varchar(16)
begin
      declare   @result   varchar(100)   
      set   @result=‘‘   
      while   @num>0  
          begin
            select   @result=substring(‘0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHLJKLMNOPQRSTUVWXYZ‘,@num%62+1,1)+@result,@num=@num/62   
          end
      return @result
  end

  private static char[] charSet = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray();
    public static string To62(long number)
    {
        var str = string.Empty;
        var num = number;
        while (num > 0)
        {
            long val = num % 62;
            str = charSet[val] + str;
            num = num / 2;
        }
        return str;
    }