Question

I have events table with columns 'title', 'description', 'start_date', 'end_date'.

I want to get ordered list live and future events, depends on 'start_date' and 'end_date'.

I try

(
    select * 
    from `events`
    where `start_date` < NOW() and `end_date` > NOW() 
    order by `start_date` desc
) 
union all
(
    select * 
    from `events`
    where `start_date` > NOW() 
    order by `start_date` desc)

but result have not that ordering which I want. I want at first ordered list by start_date live events after that ordered list by start_date future events.

Answer 1

我认为你不需要在这个联盟。只需在基本查询中添加OR条件。

然后，要将结果拆分为"this one is live"和"this one is future"，您可以使用标记

SELECT *, start_date < NOW() AS flag 
FROM `events`
WHERE (`start_date` < NOW() and `end_date` > NOW()) 
   OR `start_date` > NOW()
ORDER BY flag DESC, start_date

Nota：DESC在此向您展示您希望在未来活动之前上线。否则只需放ASC。

Answer 2

试试这个：

select * from (
(
    select start_date, end_date, 'Live' as event_type
    from `events`
    where `start_date` < NOW() and `end_date` > NOW() 
) 
union
(
    select start_date, end_date, 'Future' as event_type
    from `events`
    where `start_date` > NOW() ) ) a
ORDER BY event_type desc
, case when event_type = 'Live' then start_date end desc
, case when event_type = 'Future' then start_date end asc;

Answer 3

为什么不能选择start_date订购的所有活动？

select * 
from `events`
where (`start_date` < NOW() AND `end_date` > NOW())
or (`start_date` > NOW())
order by `start_date` desc

无论如何，直播活动将是第一次，然后是未来活动

How to union two ordered queries in the same table

3 个答案: