好的,纯 MySQL——只要你喜欢这些技巧。我需要一个变量,它初始化为要显示的期间的“开始”,通常类似于 now()。
首先只是测试数据:
create table bookingEvents
(id int not null primary key auto_increment,
timeBooked datetime,
duration int
);
insert into bookingEvents values (null, '2013-05-13 13:22:00', 15);
insert into bookingEvents values (null, '2013-05-13 15:10:00', 45);
insert into bookingEvents values (null, '2013-05-13 19:55:00', 30);
insert into bookingEvents values (null, '2013-05-14 03:22:00', 15);
insert into bookingEvents values (null, '2013-05-14 08:19:00', 15);
然后初始化“滑块”:
set @timeSlider='2013-05-10 00:00:00';
然后选择:
select if (d.name = 'Free', @timeSlider, b.timeBooked) as free_from,
if (d.name = 'Free', b.timeBooked, @timeSlider := b.timeBooked + interval b.duration minute) as free_until,
d.name as Free
from (select 1 as place, 'Free' as name union select 2 as place, 'Booked' as name) d
inner join bookingEvents b
having free_from < free_until
order by b.timeBooked, d.place;
结果:
+---------------------+---------------------+--------+
| free_from | free_until | Free |
+---------------------+---------------------+--------+
| 2013-05-10 00:00:00 | 2013-05-13 13:22:00 | Free |
| 2013-05-13 13:22:00 | 2013-05-13 13:37:00 | Booked |
| 2013-05-13 13:37:00 | 2013-05-13 15:10:00 | Free |
| 2013-05-13 15:10:00 | 2013-05-13 15:55:00 | Booked |
| 2013-05-13 15:55:00 | 2013-05-13 19:55:00 | Free |
| 2013-05-13 19:55:00 | 2013-05-13 20:25:00 | Booked |
| 2013-05-13 20:25:00 | 2013-05-14 03:22:00 | Free |
| 2013-05-14 03:22:00 | 2013-05-14 03:37:00 | Booked |
| 2013-05-14 03:37:00 | 2013-05-14 08:19:00 | Free |
| 2013-05-14 08:19:00 | 2013-05-14 08:34:00 | Booked |
+---------------------+---------------------+--------+
如果您有给定的结束时间戳,那么您必须将其预设为 @timeMaximum
set @timeSlider='2013-05-10 00:00:00';
set @timeMaximum='2013-05-14 08:35:00';
select if (d.name = 'Free', @timeSlider, b.timeBooked) as free_from,
if (d.name = 'Free', b.timeBooked, @timeSlider := b.timeBooked + interval b.duration minute) as free_until,
d.name as Free
from (select 1 as place, 'Free' as name union select 2 as place, 'Booked' as name ) as d
inner join bookingEvents b
having free_from < free_until
union select @timeSlider as free_from, @timeMaximum as free_until, 'Free' as Free
from (select 1) as d
where @timeSlider < @timeMaximum
order by free_from, free_until
;