TSQL/C# 撰寫10進制轉任何進制

以下展示C#和TSQL怎麼寫10進制，轉換成任何的進制，基本原理請參考這裡

CREATE FUNCTION dbo.f_convert_from_base10
  (@num INT, @base TINYINT)
RETURNS VARCHAR(255) AS 
BEGIN 

  -- Declarations
  DECLARE @string VARCHAR(255)
  DECLARE @return VARCHAR(255)
  DECLARE @finished BIT
  DECLARE @div INT
  DECLARE @rem INT
  DECLARE @char CHAR(1)

  -- Initialise
  SELECT @string   = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'
  SELECT @return   = CASE WHEN @num <= 0 THEN '0' ELSE '' END
  SELECT @finished = CASE WHEN @num <= 0 THEN 1 ELSE 0 END
  SELECT @base     = CASE WHEN @base < 2 OR @base IS NULL THEN 2 WHEN @base > 36 THEN 36 ELSE @base END

  -- 進制轉換迴圈
  WHILE @finished = 0
  BEGIN

    -- 數學運算
    SELECT @div = @num / @base
    SELECT @rem = @num - (@div * @base)
    SELECT @char = SUBSTRING(@string, @rem + 1, 1)
    SELECT @return = @char + @return
    SELECT @num = @div

    -- 沒有值處理?
    IF @num = 0 SELECT @finished = 1

  END

  -- 回傳結果
  RETURN @return

END
GO

C#

  public static string DecimalToArbitrarySystem(long decimalNumber, int radix)
        {
            const int BitsInLong = 64;
            const string Digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

            if (radix < 2 || radix > Digits.Length)
                throw new ArgumentException("The radix must be >= 2 and <= " + Digits.Length.ToString());

            if (decimalNumber == 0)
                return "0";

            int index = BitsInLong - 1;
            long currentNumber = Math.Abs(decimalNumber);
            char[] charArray = new char[BitsInLong];

            while (currentNumber != 0)
            {
                int remainder = (int)(currentNumber % radix);
                charArray[index--] = Digits[remainder];
                currentNumber = currentNumber / radix;
            }

            string result = new String(charArray, index + 1, BitsInLong - index - 1);
            if (decimalNumber < 0)
            {
                result = "-" + result;
            }

            return result;
        }