Question

我需要使用MySQL生成以下输出，它可以计算可用的总票数和每个事件的总票数;

event_id  event_name     start_date    tickets_available   tickets_sold
-------------------------------------------------------------------------
1         Test Event 1   2017-04-01    200                 20
2         Test Event 2   2017-04-25    100                 30

我的表格如下;

表：事件

event_id  user_id    event_name     start_date    event_active   
-------------------------------------------------------------------------
1         47         Test Event 1   2017-04-01    0                
2         47         Test Event 2   2017-04-25    0

表：ticket_types

ticket_type_id  event_id  ticket_type quantity_released quantity_remaining
---------------------------------------------------------------------------
1               1         General     100               90
2               1         VIP         100               90
3               2         General     50                30
4               2         VIP         50                40

到目前为止，这是我的SQL查询;

SELECT events.event_id, events.event_name, events.start_date, events.event_active,
(
    SELECT SUM(ticket_types.quantity_released) 
    FROM ticket_types
    WHERE ticket_types.event_id = events.event_id
) AS tickets_available,
(
    SELECT (ticket_types.quantity_released - ticket_types.quantity_remaining)
    FROM ticket_types
    WHERE ticket_types.event_id = events.event_id
) AS tickets_sold
FROM events
INNER JOIN ticket_types
ON events.event_id=ticket_types.event_id
WHERE user_id = 47;

但是，这不起作用，因为ticket_available和tickets_sold列的逻辑不正确。

有人可以帮我解决这个问题吗？

Answer 1

SELECT  EVENTS.EVENT_ID
    , EVENTS.EVENT_NAME
    , EVENTS.START_DATE
    , SUM(TICKET_TYPES.QUANTITY_RELEASED) AS TICKETS_AVAILABLE
    , SUM(TICKET_TYPES.QUANTITY_RELEASED) - SUM(TICKET_TYPES.QUANTITY_REMAINING) AS TICKETS_SOLD
FROM EVENTS
    INNER JOIN TICKET_TYPES
        ON EVENTS.EVENT_ID = TICKET_TYPES.EVENT_ID
GROUP BY EVENTS.EVENT_ID
    , EVENTS.EVENT_NAME
    , EVENTS.START_DATE;

Answer 2

由于我缺乏SQL格式的知识，因此格式不是很好，但这可能是您的解决方案。

SELECT  events.event_id,
        events.event_name,
        events.start_date,
        events.event_active,
        SUM(ticket_types.quantity_released) AS available,
        SUM(ticket_types.quantity_released) - SUM(ticket_types.quantity_remaining) AS sold
FROM events
INNER JOIN ticket_types
ON events.event_id = ticket_types.event_id
GROUP BY events.event_id
WHERE user_id = 47;

如何计算可用的总票数和使用MySQL销售的总票数？

2 个答案: