查询返回相同的总和 - oracle sql

Posted 2023-05-09

【中文标题】查询返回相同的总和 - oracle sql

【英文标题】：Query returning same sums - oracle sql

【发布时间】：2009-05-04 12:59:02

【问题描述】：

想知道是否有人可以了解我正在使用的 sql 查询；

我已经建立了这个查询；

SELECT  SUM(TICKET_TYPE.PRICE) AS TOTALCINEMASALES, CINEMA.LOCATION, PERFORMANCE.PERFORMANCE_DATE
FROM    RESERVATION, TICKET, TICKET_TYPE, CINEMA, PERFORMANCE
WHERE   TICKET_TYPE.TICKET_TYPE_ID = TICKET.TICKET_TYPE_ID
        AND TICKET.RESERVATION_ID = RESERVATION.RESERVATION_ID
        AND RESERVATION.PERFORMANCE_ID = PERFORMANCE.PERFORMANCE_ID
        AND CINEMA.LOCATION = 'SKIPTON'
        AND PERFORMANCE.PERFORMANCE_DATE BETWEEN to_date('01/03/2009','DD/MM/yyyy') AND to_date('07/04/2009','DD/MM/yyyy')
GROUP BY
       CINEMA.LOCATION, PERFORMANCE.PERFORMANCE_DATE
ORDER BY
       TOTALCINEMASALES;

每次我运行它时，它都会在每行上为 totalcinemasales 返回一组总和，但我知道数据库中有不同级别的门票销售等，它对我更改的每个位置都执行此操作，任何指针为我该如何改进它？

谢谢

【参考方案1】：

你忘了加入 CINEMA，可能是 PERFORMANCE。

猜测：

AND CINEMA.CINEMA_ID = PERFORMANCE.CINEMA_ID

你可以使用 ANSI 连接，当你习惯它时，它实际上更容易阅读：

SELECT  SUM(TICKET_TYPE.PRICE) AS TOTALCINEMASALES, CINEMA.LOCATION, PERFORMANCE.PERFORMANCE_DATE
FROM    
   TICKET 
   inner join TICKET_TYPE
     on TICKET_TYPE.TICKET_TYPE_ID = TICKET.TICKET_TYPE_ID
   inner join RESERVATION
     on TICKET.RESERVATION_ID = RESERVATION.RESERVATION_ID
   inner join PERFORMANCE
     on RESERVATION.PERFORMANCE_ID = PERFORMANCE.PERFORMANCE_ID
   inner join CINEMA  /* the missing link */
     on CINEMA.CINEMA_ID = PERFORMANCE.CINEMA_ID
WHERE
   CINEMA.LOCATION = 'SKIPTON'
   AND PERFORMANCE.PERFORMANCE_DATE BETWEEN to_date('01/03/2009','DD/MM/yyyy') AND to_date('07/04/2009','DD/MM/yyyy')
GROUP BY
       CINEMA.LOCATION, PERFORMANCE.PERFORMANCE_DATE
ORDER BY
       TOTALCINEMASALES;

【讨论】：

谢谢，你看不到的是（可能是看了你的建议后出现问题的原因）是没有从表演到电影的直接链接，我用过cinema>screen(cinema_id) >run(screen_id>>performance(run_id) - 我应该包括这两个表并为链接添加“和”吗？还是 ansi 连接，尽管我觉得我需要更多地听到我的声音。

是的，你需要加入所有的表。如果不这样做，您将获得笛卡尔积，这意味着返回 Cinema 和连接的其他表的所有组合。要了解我的意思，请从 select 子句中删除 group by 子句和 SUM。使用过滤器，您可以删除所有无用的组合。

【参考方案2】：

SELECT  SUM(TICKET_TYPE.PRICE) AS TOTALCINEMASALES, CINEMA.LOCATION, PERFORMANCE.PERFORMANCE_DATE
FROM    RESERVATION, TICKET, TICKET_TYPE, CINEMA, PERFORMANCE
WHERE   TICKET_TYPE.TICKET_TYPE_ID = TICKET.TICKET_TYPE_ID
        AND TICKET.RESERVATION_ID = RESERVATION.RESERVATION_ID
        AND RESERVATION.PERFORMANCE_ID = PERFORMANCE.PERFORMANCE_ID
        AND CINEMA.LOCATION = 'SKIPTON'
-- Added this
        AND PERFORMANCE.CINEMA_ID = CINEMA.CINEMA_ID
--
        AND PERFORMANCE.PERFORMANCE_DATE BETWEEN to_date('01/03/2009','DD/MM/yyyy') AND to_date('07/04/2009','DD/MM/yyyy')
GROUP BY
        CINEMA.LOCATION, PERFORMANCE.PERFORMANCE_DATE
ORDER BY
        TOTALCINEMASALES;