I'm trying to write a mySQL procedure with a cursor to calculate a fare. I pass in the stationid's then I figure out what zone they are in. The fare is a set value of $1 and an additional $0.20 for each zone traveled in. The code I have so far runs but there is a problem with the cursor not fetching the values into the variables.
Any help would be greatly appreciated. Thanks
Tables:
DROP DATABASE IF EXISTS luasSystem;
CREATE DATABASE luasSystem;
USE luasSystem;
CREATE TABLE IF NOT EXISTS line
(
line_id INT NOT NULL AUTO_INCREMENT,
Line_colour CHAR(10) NOT NULL,
PRIMARY KEY (line_id)
) ENGINE=InnoDB;
CREATE TABLE IF NOT EXISTS zone
(
zone_id INT NOT NULL AUTO_INCREMENT,
zone_name VARCHAR(20) NOT NULL,
line INT NOT NULL,
PRIMARY KEY (zone_id),
FOREIGN KEY (line) REFERENCES line(line_id) ON UPDATE CASCADE ON DELETE RESTRICT
) ENGINE=InnoDB;
CREATE TABLE IF NOT EXISTS station
(
station_id INT NOT NULL AUTO_INCREMENT,
station_name CHAR(20) NOT NULL,
service CHAR(20),
line INT NOT NULL,
zone INT NOT NULL,
PRIMARY KEY (station_id),
FOREIGN KEY (line) REFERENCES line(line_id) ON UPDATE CASCADE ON DELETE RESTRICT,
FOREIGN KEY (zone) REFERENCES zone(zone_id) ON UPDATE CASCADE ON DELETE RESTRICT
) ENGINE=InnoDB;
Stored Procedure:
DROP PROCEDURE IF EXISTS calculateFare;
DELIMITER //
CREATE PROCEDURE calculateFare
(
IN stationid1 INT, IN stationid2 INT
)
BEGIN
DECLARE zoneNum1 INT;
DECLARE zoneNum2 INT;
DECLARE num INT;
DECLARE fare DOUBLE;
DECLARE tableEnd BOOLEAN;
DECLARE zoneCur CURSOR FOR
SELECT zone, zone FROM station
WHERE station_name = stationid1 AND station_name = stationid2;
DECLARE CONTINUE HANDLER FOR NOT FOUND
SET tableEnd = TRUE;
OPEN zoneCur;
the_loop: LOOP
FETCH zoneCur
INTO zoneNum1, zoneNum2;
IF tableEnd THEN
CLOSE zoneCur;
LEAVE the_loop;
END IF;
SET fare = 1;
SET num = 0;
IF zoneNum1 < zoneNum2 THEN
SET num = zoneNum2 - zoneNum1;
ELSEIF zoneNum1 > zoneNum2 THEN
SET num = zoneNum1 - zoneNum2;
END IF;
SET fare = (num * 0.20) + 1;
SELECT fare;
END LOOP the_loop;
END //
DELIMITER ;
CAll calculateFare(3,5);