可预约答案 - 爱码网

【问题标题】：Available appointments可预约
【发布时间】：2012-09-06 19:34:31
【问题描述】：

我有两个 mysql 表，日程表和约会。在日程表中有定义的医生终端，而在其他有预定的约会。问题是医生总是可以更改他的终端，我不能在约会表中粘贴参考，我只想在一个 mysql 查询中为两位医生获取可用的终端。那可能吗？

CREATE TABLE `schedule` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `from` timestamp NULL DEFAULT NULL,
  `to` timestamp NULL DEFAULT NULL,
  `doctor_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=latin1;


INSERT INTO `schedule` (`id`, `from`, `to`, `doctor_id`)
VALUES
    (1, '2012-09-06 14:00:00', '2012-09-06 14:59:59', 1),
    (2, '2012-09-06 15:00:00', '2012-09-06 15:59:59', 1),
    (3, '2012-09-06 16:00:00', '2012-09-06 16:59:59', 1),
    (4, '2012-09-06 17:00:00', '2012-09-06 17:59:59', 1),
    (5, '2012-09-06 14:00:00', '2012-09-06 14:59:59', 2),
    (6, '2012-09-06 15:00:00', '2012-09-06 15:59:59', 2),
    (7, '2012-09-06 16:00:00', '2012-09-06 16:59:59', 2),
    (8, '2012-09-06 17:00:00', '2012-09-06 17:59:59', 2);

CREATE TABLE `appointments` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `from` timestamp NULL DEFAULT NULL,
  `to` timestamp NULL DEFAULT NULL,
  `doctor_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=latin1;


INSERT INTO `appointments` (`id`, `from`, `to`, `doctor_id`)
VALUES
    (3, '2012-09-06 16:00:00', '2012-09-06 16:59:59', 1),
    (4, '2012-09-06 17:00:00', '2012-09-06 17:59:59', 1),
    (5, '2012-09-06 14:00:00', '2012-09-06 14:59:59', 2),
    (8, '2012-09-06 17:00:00', '2012-09-06 17:59:59', 2);

【问题讨论】：

“终端”是什么意思？你可以解释吗？另外，您问了很多问题，但没有接受任何答案。要接受答案，请单击绿色复选框。
约会 ID 是否总是它链接到的日程表行的 ID？
Id不一样，我只是把粘贴记录从一个表复制到另一个。

标签： mysql

【解决方案1】：

如果保证约会 id 与日程表 id 相等，则：

select `id`,`from`,`to`,`doctor_id`
from schedule
where `id` not in 
(select `id` from appointments)
order by `doctor_id`,`from`

Sqlfiddle

如果不能保证约会 id 被链接，那么：

select `id`,`from`,`to`,`doctor_id`
from schedule
where `id` not in 
(select `t1`.`id` 
from(
select `s`.`id`,`s`.`from`,`s`.`to`,`s`.`doctor_id` 
from schedule as s 
inner join 
appointments as a
on `s`.`doctor_id`=`a`.`doctor_id`
and `s`.`from`=`a`.`from`
and `s`.`to`=`a`.`to`)
as t1)

Sqlfiddle

【讨论】：