mySQL存儲過程 - 光標錯誤

Question

我正在嘗試用光標編寫mySQL過程來計算票價。我通過stationid，然後我找出他們在哪個區域。票價是1美元的設定值，並且每個區域的額外費用爲0.20美元。 我到目前爲止的代碼已經運行，但是遊標存在問題將值提取到變量中。

任何幫助將不勝感激。由於

表：

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; 

存儲過程：你使用十進制值，而不是整數

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); 

Answer 1

這豈不是更容易？建議你看看：http://dev.mysql.com/doc/refman/5.0/en/fixed-point-types.html