【发布时间】:2012-10-26 00:06:06
【问题描述】:
所以这是我最新的 endeaver .. 尝试添加子查询的结果以获取另一个字段或总计...但是总而言之,这个 simple 语法似乎不起作用.. 有人可以请指出正确的方向...提前谢谢
SELECT
sub_events.name AS sub_event,
clients.name AS client,
divisions.name AS division,
subdivisions.name AS subdivision,
(SELECT CONCAT(name,' ',surname) FROM users WHERE id = bookings.host_id) AS host,
CONCAT(users.name,' ',users.surname) AS name,
(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 1 AND itinerary_booking_id = 1 AND booking_id = bookings.id AND client_cost IS NOT NULL) AS flight,
(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 1 and itinerary_booking_id = 2 AND booking_id = bookings.id AND client_cost IS NOT NULL) AS flight_change,
(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 2 AND itinerary_booking_id = 1 AND booking_id = bookings.id AND client_cost IS NOT NULL) AS hotel,
(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 2 and itinerary_booking_id = 3 AND booking_id = bookings.id AND client_cost IS NOT NULL) AS hotel_change,
(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 3 AND itinerary_booking_id = 1 AND booking_id = bookings.id AND client_cost IS NOT NULL) AS transfer,
(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 3 AND itinerary_booking_id = 4 AND booking_id = bookings.id AND client_cost IS NOT NULL) AS transfer_change
(SELECT SUM((SELECT client_cost FROM itineraries WHERE itinerary_type_id = 3 AND itinerary_booking_id = 4 AND booking_id = bookings.id AND client_cost IS NOT NULL)
+(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 1 and itinerary_booking_id = 2 AND booking_id = bookings.id AND client_cost IS NOT NULL)
+(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 2 AND itinerary_booking_id = 1 AND booking_id = bookings.id AND client_cost IS NOT NULL)
+(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 2 and itinerary_booking_id = 3 AND booking_id = bookings.id AND client_cost IS NOT NULL)
+(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 3 AND itinerary_booking_id = 1 AND booking_id = bookings.id AND client_cost IS NOT NULL)
+(SELECT client_cost FROM itineraries WHERE itinerary_type_id = 3 AND itinerary_booking_id = 4 AND booking_id = bookings.id AND client_cost IS NOT NULL)) AS Total)
FROM users
JOIN bookings ON bookings.guest_id = users.id
JOIN clients ON users.client_id = bookings.client_id
JOIN details ON details.user_id = users.id
JOIN divisions ON divisions.client_id = users.client_id
JOIN subdivisions ON subdivisions.division_id = bookings.division_id
JOIN sub_events ON sub_events.id = bookings.sub_event_id
JOIN itineraries ON itineraries.booking_id = bookings.id
GROUP BY bookings.id`
【问题讨论】:
-
什么具体不起作用?
-
我无法得到子查询的总和...
-
使用 SUM 和 GROUP BY 时,需要在 GROUP BY 子句中列出所有未聚合的列。 MySQL 为 GROUP BY 提供了一个非标准扩展,称为隐藏列。但是真的很难用。在尝试调试查询之前,请阅读并理解此网页 dev.mysql.com/doc/refman/5.0/en/group-by-hidden-columns.html。
-
这是一个可怕的查询,由于大量相关的子查询,它的执行就像垃圾一样。您可以通过简单地加入
itineraries和一些if或case语句来实现所有这些。