DELIMITER $$

CREATE FUNCTION MakeRandomEncryptPattern()
RETURNS VARCHAR(62)
DETERMINISTIC
BEGIN
    DECLARE strOrder VARCHAR(62) DEFAULT '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    DECLARE strResult VARCHAR(62) DEFAULT '';
    DECLARE nRand INT;
    DECLARE i INT DEFAULT LENGTH(strOrder);

    WHILE i > 0 DO
        SET nRand = FLOOR(RAND() * i);
        SET strResult = CONCAT(strResult, SUBSTRING(strOrder, nRand + 1, 1));
        SET strOrder = CONCAT(SUBSTRING(strOrder, 1, nRand), SUBSTRING(strOrder, nRand + 2));
        SET i = i - 1;
    END WHILE;

    RETURN strResult;
END$$

DELIMITER ;


DELIMITER $$

CREATE FUNCTION MakeDecryptPattern(strPattern_Encrypt VARCHAR(62))
RETURNS VARCHAR(62)
DETERMINISTIC
BEGIN
    DECLARE strOrder VARCHAR(62) DEFAULT '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    DECLARE strResult VARCHAR(62) DEFAULT '';
    DECLARE chChar CHAR(1);
    DECLARE nPos INT;

    SET i = 1;
    WHILE i <= LENGTH(strOrder) DO
        SET chChar = SUBSTRING(strOrder, i, 1);
        SET nPos = LOCATE(chChar, strPattern_Encact);
        IF nPos > 0 THEN
            SET strResult = CONCAT(strResult, SUBSTRING(strPattern_Encrypt, nPos, 1));
        END IF;
        SET i = i + 1;
    END WHILE;

    RETURN strResult;
END$$

DELIMITER ;