DELIMITER $$

CREATE FUNCTION wordcount(str TEXT)

       RETURNS INT

       DETERMINISTIC

       SQL SECURITY INVOKER

       NO SQL

  BEGIN

    DECLARE wordCnt, idx, maxIdx INT DEFAULT 0;

    DECLARE currChar, prevChar BOOL DEFAULT 0;

    SET maxIdx=char_length(str);

    WHILE idx < maxIdx DO

        SET currChar=SUBSTRING(str, idx, 1) RLIKE '[[:alnum:]]';

        IF NOT prevChar AND currChar THEN

            SET wordCnt=wordCnt+1;

        END IF;

        SET prevChar=currChar;

        SET idx=idx+1;

    END WHILE;

    RETURN wordCnt;

  END

$$

DELIMITER ;