why they make me do it with sql

CREATE FUNCTION ufn_IsWordComprised(@setOfLetters VARCHAR(MAX), @word VARCHAR(MAX))
RETURNS BIT
AS
BEGIN
  DECLARE @why BIT = 0;
  DECLARE @cindex INT = 1;
  DECLARE @cchar CHAR;

  WHILE(@cindex <= LEN(@word))
  BEGIN

    SET @cchar = SUBSTRING(@word, @cindex, 1);
    IF(CHARINDEX(@cchar, @setOfLetters) = 0)
      RETURN @why;
    SET @cindex += 1;

  END

  RETURN @why+ 1;

END