sql - SQL 子选择查询

Question

我正在尝试查询酒店数据库以查找预订的总费用。我正在使用子选择查询，但是我经常收到错误消息。

这是查询，我希望它显示预订 ID 和房间号以及总费用。

    SELECT BOOKING_ID, ROOM_NO , SUM(TOTAL) AS TOTAL FROM
    (
        SELECT (END_DATE-START_DATE) DAYDIFF, ((END_DATE-START_DATE)*ROOM_PRICE) TOTAL_ROOM 
        FROM ROOM_TBL NATURAL JOIN ROOM_DETAILS_TBL WHERE BOOKING_ID = &BOOKING_ID
    )  FROM ROOM_TBL; 

这是错误：

ERROR at line 3:
ORA-00907: missing right parenthesis

Answer 1

虽然我不确定您的架构中的各种属性在哪里，但试试这个：

SELECT z.BOOKING_ID, r.ROOM_NO , SUM(TOTAL) TOTAL 
FROM  (SELECT ri.room_No, dt.Booking_id,
             (END_DATE-START_DATE) DAYDIFF, 
             ((END_DATE-START_DATE)*ROOM_PRICE) TOTAL 
       FROM ROOM_TBL ri
             NATURAL JOIN ROOM_DETAILS_TBL dt
       WHERE BOOKING_ID = &BOOKING_ID) z 
   Join ROOM_TBL r  
     On r.ROOM_NO = z.Room_No   

Answer 2

那么你有几个问题。

首先，查询中有两个FROMs，一个在子查询之前，一个在子查询之后。

其次，你没有GROUP BY，但你有一个正在使用的聚合函数。

看起来你可能想要：

SELECT BOOKING_ID, ROOM_NO , SUM(TOTAL) AS TOTAL 
FROM
(
    SELECT BOOKING_ID, 
        ROOM_NO, 
        (END_DATE-START_DATE) DAYDIFF, 
        ((END_DATE-START_DATE)*ROOM_PRICE) TOTAL 
    FROM ROOM_TBL 
    NATURAL JOIN ROOM_DETAILS_TBL 
    WHERE BOOKING_ID = &BOOKING_ID
)  
GROUP BY BOOKING_ID, ROOM_NO;

编辑，如果你想要TOTAL一行，那么你可以使用GROUP BY ROLLUP：

SELECT max(BOOKING_ID) Booking_id, 
  case when ROOM_NO is null then ' ' else room_no end Room_no, 
  SUM(TOTAL) AS TOTAL 
FROM
(
    SELECT BOOKING_ID, 
        ROOM_NO, 
        (END_DATE-START_DATE) DAYDIFF, 
        ((END_DATE-START_DATE)*ROOM_PRICE) TOTAL 
    FROM ROOM_TBL 
    NATURAL JOIN ROOM_DETAILS_TBL 
    WHERE BOOKING_ID = &BOOKING_ID
)  
GROUP BY ROLLUP (room_no);

请参阅带有演示的 SQL Fiddle

如果您想要列中的数据，则可以在子查询上使用公用表表达式：

with cte as
(
     SELECT BOOKING_ID, 
        ROOM_NO, 
        (END_DATE-START_DATE) DAYDIFF, 
        ((END_DATE-START_DATE)*ROOM_PRICE) TOTAL 
    FROM ROOM_TBL 
    NATURAL JOIN ROOM_DETAILS_TBL 
 )
 select booking_id,
    room_no,
    total,
    case when rn = 1 then totalbooking else null end totalbooking     
 from
 (
     select booking_id,
        room_no,
        total,
        (select sum(total) from cte) TotalBooking,
        row_number() over(partition by booking_id order by room_no) rn
     from cte
 ) 

请参阅带有演示的 SQL Fiddle