Question

希望有人可以帮助解决我在oracle中构建查询时遇到的问题。

我是oracle的新手，尽管我对sql有一些了解 -

这是一个电影预订系统场景 - 我试图让下面的sql输出一行，这是特定电影院特定演出所售票的总和。我已经到了下面，虽然它列出了所有12次出现，当我想要它说出售12张门票等。

我在查询构建器中初始化了这个，然后通过manualy添加了count和group。

对于我如何实现这一点，或者我可能出错的地方，我们都非常感激。

感谢您的光临。

select count(ticket.ticket_id) as tickets_sold, "PERFORMANCE"."PERFORMANCE_DATE" as "PERFORMANCE_DATE",
     "FILM"."FILM_TITLE" as "FILM_TITLE",
     "TICKET"."TICKET_ID" as "TICKET_ID",
     "CINEMA"."LOCATION" as "LOCATION",
     "PERFORMANCE"."PERFORMANCE_TIME" as "PERFORMANCE_TIME" 
 from    "TICKET" "TICKET",
     "RESERVATION" "RESERVATION",
     "PERFORMANCE" "PERFORMANCE",
     "RUN" "RUN",
     "SCREEN" "SCREEN",
     "CINEMA" "CINEMA",
     "FILM" "FILM" 
 where   "PERFORMANCE"."PERFORMANCE_ID"="RESERVATION"."PERFORMANCE_ID"
 and     "PERFORMANCE"."RUN_ID"="RUN"."RUN_ID"
 and     "RUN"."FILM_ID"="FILM"."FILM_ID"
 and     "RUN"."SCREEN_ID"="SCREEN"."SCREEN_ID"
 and     "SCREEN"."CINEMA_ID"="CINEMA"."CINEMA_ID"
 and     "TICKET"."RESERVATION_ID"="RESERVATION"."RESERVATION_ID"
  and    "PERFORMANCE"."PERFORMANCE_DATE" ='1-mar-09' 
   and   "FILM"."FILM_TITLE" ='PIRATES OF THE CARIBBEAN - AT WORLDS END' 
   and   "CINEMA"."LOCATION" ='bradfordeast' 
   and   "PERFORMANCE"."PERFORMANCE_TIME" ='20:00' group by reservation.performance_id, performance.performance_date, film.film_title, ticket.ticket_id,cinema.location, performance.performance_time order by tickets_sold DESC;

输出：

TICKETS_SOLD PERFORMANCE_DATE FILM_TITLE TICKET_ID LOCATION PERFORMANCE_TIME 

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 485 bradfordeast 20:00

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 488 bradfordeast 20:00

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 484 bradfordeast 20:00 

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 491 bradfordeast 20:00

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 493 bradfordeast 20:00 

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 495 bradfordeast 20:00

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 489 bradfordeast 20:00

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 487 bradfordeast 20:00 

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 490 bradfordeast 20:00 

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 492 bradfordeast 20:00 

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 494 bradfordeast 20:00 

1 01-MAR-09 PIRATES OF THE CARIBBEAN - AT WORLDS END 486 bradfordeast 20:00

Answer 1

ticket_id时包含COUNT(ticket_id)和GROUP BY ticket_id是没有意义的。

我推断您的架构具有如下关系：

TICKETS --> RESERVATION --> PERFORMANCE --> RUN --> SCREEN --> CINEMA
                                   FILM --> RUN

看起来您想要的报告可以描述如下：

计算每部电影的票数，演出日期和时间。时间和电影院的位置。

在使用GROUP BY的任何查询中，SELECT - 列中的列与GROUP BY列表中的列匹配很重要（除COUNT()等聚合函数中的列外}）。这称为单值规则，它在标准SQL中强制执行。这些是报告说明中“per”后面的列。

以下是我编写查询的方法：

SELECT COUNT(t."TICKET_ID") AS tickets_sold, 
 f."FILM_TITLE",
 c."LOCATION",
 p."PERFORMANCE_DATE",
 p."PERFORMANCE_TIME",
FROM "TICKET" t,
 JOIN "RESERVATION" r ON (r."RESERVATION_ID" = t."RESERVATION_ID") 
 JOIN "PERFORMANCE" p ON (p."PERFORMANCE_ID" = r."PERFORMANCE_ID")
 JOIN "RUN" run ON (run."RUN_ID" = p."RUN_ID")
 JOIN "SCREEN" s ON (s."SCREEN_ID" = run."SCREEN_ID")
 JOIN "CINEMA" c ON (c."CINEMA_ID" = s."CINEMA_ID")
 JOIN "FILM" f ON (f."FILM_ID" = run."FILM_ID")
WHERE p."PERFORMANCE_DATE" ='1-mar-09'
 AND f."FILM_TITLE" ='PIRATES OF THE CARIBBEAN - AT WORLDS END' 
 AND c."LOCATION" ='bradfordeast' 
 AND p."PERFORMANCE_TIME" ='20:00'
GROUP BY f."FILM_TITLE", c."LOCATION", p."PERFORMANCE_DATE", p."PERFORMANCE_TIME" 
ORDER BY tickets_sold DESC;

请注意，我使用标准JOIN语法，将连接条件移动到ON子句中。 WHERE子句仅包含查询限制。从逻辑上讲，查询结果没有区别，但为了清楚起见，我更喜欢将连接条件保持在FROM子句中的各个表附近。

我还使用单字母表别名来提高可读性（r与run除外，因为它们都以r开头。

Answer 2

您需要从group子句中排除“ticket.ticket_id”（这个唯一值会产生不必要的组 - 结果字符串）：

select count(ticket.ticket_id) as tickets_sold, "PERFORMANCE"."PERFORMANCE_DATE" as "PERFORMANCE_DATE",
         "FILM"."FILM_TITLE" as "FILM_TITLE",
         "TICKET"."TICKET_ID" as "TICKET_ID",
         "CINEMA"."LOCATION" as "LOCATION",
         "PERFORMANCE"."PERFORMANCE_TIME" as "PERFORMANCE_TIME" 
     from    "TICKET" "TICKET",
         "RESERVATION" "RESERVATION",
         "PERFORMANCE" "PERFORMANCE",
         "RUN" "RUN",
         "SCREEN" "SCREEN",
         "CINEMA" "CINEMA",
         "FILM" "FILM" 
     where   "PERFORMANCE"."PERFORMANCE_ID"="RESERVATION"."PERFORMANCE_ID"
     and     "PERFORMANCE"."RUN_ID"="RUN"."RUN_ID"
     and     "RUN"."FILM_ID"="FILM"."FILM_ID"
     and     "RUN"."SCREEN_ID"="SCREEN"."SCREEN_ID"
     and     "SCREEN"."CINEMA_ID"="CINEMA"."CINEMA_ID"
     and     "TICKET"."RESERVATION_ID"="RESERVATION"."RESERVATION_ID"
      and    "PERFORMANCE"."PERFORMANCE_DATE" ='1-mar-09' 
       and   "FILM"."FILM_TITLE" ='PIRATES OF THE CARIBBEAN - AT WORLDS END' 
       and   "CINEMA"."LOCATION" ='bradfordeast' 
       and   "PERFORMANCE"."PERFORMANCE_TIME" ='20:00'
group by reservation.performance_id, performance.performance_date,
film.film_title, ticket.ticket_id,cinema.location, performance.performance_time
order by tickets_sold DESC;

Oracle count语句问题

2 个答案: