Fibonacci (english)

#
# Return the first <number_seq> numbers of Fibonacci sequence,
# omits (<omit_0>) or not the initial zero
#

DELIMITER |
CREATE OR REPLACE FUNCTION Fibonacci( number_seq INT, omit_0 BOOLEAN) RETURNS VARCHAR( 512) DETERMINISTIC NO SQL
BEGIN
    DECLARE first INT DEFAULT 0;
    DECLARE second INT DEFAULT 1;
    DECLARE temporary INT DEFAULT 0;
    DECLARE cont INT DEFAULT 0;
    DECLARE acumulator VARCHAR( 512) DEFAULT "";

    IF omit_0 THEN
        SET first = 1;
    END IF;

    IF number_seq > 0 THEN
        SET acumulator = cast( first AS CHAR);
    END IF;

    IF number_seq > 1 THEN
        SET acumulator = concat( acumulator, ' / ', second);
    END IF;

    IF number_seq > 2 THEN
        REPEAT
            SET temporary = second;
            SET second = second + first;
            SET first := temporary;

            SET acumulator = concat( acumulator, ' / ', second);

            SET cont := cont + 1;
        UNTIL cont = number_seq - 2 END REPEAT;
    END IF;

    RETURN acumulator;
END |