MySQL 到 select 交通时刻表
MySQL to select a transport schedule
我正在开发一个 MySQL 数据库来处理运输时间表。每条火车线路或公共汽车旅程都有一个唯一标识符，从 start 到 finish 的旅程可能不会停靠所有可能的停靠点。
我有三个table：时刻表、车站和旅程。后两者目前只包含一个自增id和varchar标识符。 schedule table包含自增id，s_id和j_id（分别指站和旅程id），stop_order和arrival/departure次.
运行宁此 SQL:
SELECT schedules.id, journeys.journey, stations.station, schedules.s_order,
schedules.a_time, schedules.d_time
FROM `schedules`
JOIN `journeys` ON schedules.j_id = journeys.j_id
JOIN `stations` ON schedules.s_id = stations.s_id
returns这个结果：
+----+---------+---------+---------+----------+----------+
| id | journey | station | s_order | a_time | d_time |
+----+---------+---------+---------+----------+----------+
| 1 | J1 | STA | 1 | NULL | 07:00:00 |
| 2 | J1 | STB | 2 | 07:09:00 | 07:10:00 |
| 3 | J1 | STC | 3 | 07:29:00 | 07:30:00 |
| 4 | J1 | STD | 4 | 07:44:00 | 07:45:00 |
| 5 | J1 | STE | 5 | 07:59:00 | 08:00:00 |
| 6 | J1 | STF | 6 | 08:15:00 | NULL |
| 7 | J2 | STA | 1 | NULL | 07:30:00 |
| 8 | J2 | STC | 2 | 07:59:00 | 08:00:00 |
| 9 | J2 | STF | 3 | 08:45:00 | NULL |
| 10 | J3 | STA | 1 | NULL | 08:00:00 |
| 11 | J3 | STB | 2 | 08:09:00 | 08:10:00 |
| 12 | J3 | STD | 3 | 08:44:00 | 08:45:00 |
| 13 | J3 | STE | 4 | 09:00:00 | NULL |
| 14 | J4 | STA | 1 | NULL | 08:30:00 |
| 15 | J4 | STD | 2 | 09:14:00 | 09:15:00 |
| 16 | J4 | STF | 3 | 09:45:00 | NULL |
| 17 | J5 | STF | 1 | NULL | 07:10:00 |
| 18 | J5 | STE | 2 | 07:24:00 | 07:25:00 |
| 19 | J5 | STD | 3 | 07:39:00 | 07:40:00 |
| 20 | J5 | STC | 4 | 07:54:00 | 07:55:00 |
| 21 | J5 | STB | 5 | 08:14:00 | 08:15:00 |
| 22 | J5 | STA | 6 | 08:25:00 | NULL |
| 23 | J6 | STF | 1 | NULL | 07:30:00 |
| 24 | J6 | STC | 2 | 08:14:00 | 08:15:00 |
| 25 | J6 | STA | 3 | 08:45:00 | NULL |
| 26 | J7 | STE | 1 | NULL | 08:00:00 |
| 27 | J7 | STD | 2 | 08:14:00 | 08:15:00 |
| 28 | J7 | STB | 3 | 08:49:00 | 08:50:00 |
| 29 | J7 | STA | 4 | 09:00:00 | NULL |
| 30 | J8 | STF | 1 | NULL | 08:20:00 |
| 31 | J8 | STD | 2 | 08:49:00 | 08:50:00 |
| 32 | J8 | STA | 3 | 09:35:00 | NULL |
+----+---------+---------+---------+----------+----------+
每个方向有四个行程（J1 到 J8）。
我需要能够回答以下问题：
哪些行程从 STB 到 STD（回答 J1 和 J3）但不包括相反方向的行程（J5 和 J7）？
哪些行程在 STC 停靠（回答 J1、J2、J5 和 J6）？
我试过子查询、自连接、创建临时 table 然后查询它，但我的头撞到了砖墙上。我什至不知道我的 table 的设计是否最优。
最后，这里是创建和填充 table 的 SQL：
CREATE TABLE `journeys` (
`id` int(11) NOT NULL,
`j_id` int(11) NOT NULL,
`journey` varchar(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `journeys` (`id`, `j_id`, `journey`) VALUES
(1, 1, 'J1'),
(2, 2, 'J2'),
(3, 3, 'J3'),
(4, 4, 'J4'),
(5, 5, 'J5'),
(6, 6, 'J6'),
(7, 7, 'J7'),
(8, 8, 'J8');
.
CREATE TABLE `stations` (
`id` int(11) NOT NULL,
`s_id` int(11) NOT NULL,
`station` varchar(3) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `stations` (`id`, `s_id`, `station`) VALUES
(1, 1, 'STA'),
(2, 2, 'STB'),
(3, 3, 'STC'),
(4, 4, 'STD'),
(5, 5, 'STE'),
(6, 6, 'STF');
.
CREATE TABLE `schedules` (
`id` int(11) NOT NULL,
`j_id` int(11) NOT NULL,
`s_id` int(11) NOT NULL,
`s_order` int(11) NOT NULL,
`a_time` time DEFAULT NULL,
`d_time` time DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `schedules` (`id`, `j_id`, `s_id`, `s_order`, `a_time`, `d_time`)
VALUES
(1, 1, 1, 1, NULL, '07:00:00'),
(2, 1, 2, 2, '07:09:00', '07:10:00'),
(3, 1, 3, 3, '07:29:00', '07:30:00'),
(4, 1, 4, 4, '07:44:00', '07:45:00'),
(5, 1, 5, 5, '07:59:00', '08:00:00'),
(6, 1, 6, 6, '08:15:00', NULL),
(7, 2, 1, 1, NULL, '07:30:00'),
(8, 2, 3, 2, '07:59:00', '08:00:00'),
(9, 2, 6, 3, '08:45:00', NULL),
(10, 3, 1, 1, NULL, '08:00:00'),
(11, 3, 2, 2, '08:09:00', '08:10:00'),
(12, 3, 4, 3, '08:44:00', '08:45:00'),
(13, 3, 5, 4, '09:00:00', NULL),
(14, 4, 1, 1, NULL, '08:30:00'),
(15, 4, 4, 2, '09:14:00', '09:15:00'),
(16, 4, 6, 3, '09:45:00', NULL),
(17, 5, 6, 1, NULL, '07:10:00'),
(18, 5, 5, 2, '07:24:00', '07:25:00'),
(19, 5, 4, 3, '07:39:00', '07:40:00'),
(20, 5, 3, 4, '07:54:00', '07:55:00'),
(21, 5, 2, 5, '08:14:00', '08:15:00'),
(22, 5, 1, 6, '08:25:00', NULL),
(23, 6, 6, 1, NULL, '07:30:00'),
(24, 6, 3, 2, '08:14:00', '08:15:00'),
(25, 6, 1, 3, '08:45:00', NULL),
(26, 7, 5, 1, NULL, '08:00:00'),
(27, 7, 4, 2, '08:14:00', '08:15:00'),
(28, 7, 2, 3, '08:49:00', '08:50:00'),
(29, 7, 1, 4, '09:00:00', NULL),
(30, 8, 6, 1, NULL, '08:20:00'),
(31, 8, 4, 2, '08:49:00', '08:50:00'),
(32, 8, 1, 3, '09:35:00', NULL);
我希望我已经提供了足够的信息以便有人能够提供帮助。
感谢您的时间和耐心等待。
*****更新*****
好的，所以我取得了一些进展。 运行 以下 SQL 在单独的段中（如果我 运行 一起出错）：
DROP TEMPORARY TABLE IF EXISTS tableSTART;
.
DROP TEMPORARY TABLE IF EXISTS tableEND;
.
CREATE TEMPORARY TABLE IF NOT EXISTS tableSTART AS
(
SELECT schedules.id, journeys.journey, stations.station, schedules.s_order,
schedules.a_time, schedules.d_time
FROM `schedules`
JOIN `journeys` ON schedules.j_id = journeys.j_id
JOIN `stations` ON schedules.s_id = stations.s_id
WHERE stations.station = "STB"
);
.
CREATE TEMPORARY TABLE IF NOT EXISTS tableEND AS
(
SELECT schedules.id, journeys.journey, stations.station, schedules.s_order,
schedules.a_time, schedules.d_time
FROM `schedules`
JOIN `journeys` ON schedules.j_id = journeys.j_id
JOIN `stations` ON schedules.s_id = stations.s_id
WHERE stations.station = "STE"
);
.
select ts.journey, ts.station startStn, ts.s_order startOrder, te.journey,
te.station endStn, te.s_order endOrder
from tableSTART ts
cross join tableEND te
这显示了旅程、起点 (STB) 和终点 (STE) 站以及起点站和终点站的车站顺序。我如何过滤它以仅留下开始顺序小于结束顺序的那些旅程（即从 STB 到 STE 并排除从 STE 到 STB 的旅程？
提前致谢。
从 STB 到 STD 有哪些行程？
我们想要这样的旅程：
- 在 STB 有一些预定的停留
- 有一些（其他）停止在 STD
- 在 STD 之前停在 STB
select j.journey
from journeys j
-- have some scheduled stop at STB
join schedules sc1 on sc1.j_id = j.id
join stations st1 on st1.id = sc1.s_id
and st1.station = 'STB'
-- have some (other) stop scheduled at STD
join schedules sc2 on sc2.j_id = j.id
join stations st2 on st2.id = sc2.s_id
and st2.station = 'STD'
-- stop at STB before STD
where sc1.s_order < sc2.s_order;
注意你也可以这样写：
select j.journey
from journeys j
join schedules sc1 on sc1.j_id = j.id
join stations st1 on st1.id = sc1.s_id
join schedules sc2 on sc2.j_id = j.id
join stations st2 on st2.id = sc2.s_id
where st1.station = 'STB'
and st2.station = 'STD'
and sc1.s_order < sc2.s_order;
（将条件放入内部联接的 on 与将它们放入 where 相同）
哪些旅程在 STC 停靠？
（可能是微不足道的，在上面之后）
select j.journey
from journeys j
join schedules sc on sc.j_id = j.id
join stations st on st.id = sc.s_id
where st.station = 'STC';
请注意，这正是您使用较少列和 where :)
的查询
我正在开发一个 MySQL 数据库来处理运输时间表。每条火车线路或公共汽车旅程都有一个唯一标识符，从 start 到 finish 的旅程可能不会停靠所有可能的停靠点。
我有三个table：时刻表、车站和旅程。后两者目前只包含一个自增id和varchar标识符。 schedule table包含自增id，s_id和j_id（分别指站和旅程id），stop_order和arrival/departure次.
运行宁此 SQL:
SELECT schedules.id, journeys.journey, stations.station, schedules.s_order,
schedules.a_time, schedules.d_time
FROM `schedules`
JOIN `journeys` ON schedules.j_id = journeys.j_id
JOIN `stations` ON schedules.s_id = stations.s_id
returns这个结果：
+----+---------+---------+---------+----------+----------+
| id | journey | station | s_order | a_time | d_time |
+----+---------+---------+---------+----------+----------+
| 1 | J1 | STA | 1 | NULL | 07:00:00 |
| 2 | J1 | STB | 2 | 07:09:00 | 07:10:00 |
| 3 | J1 | STC | 3 | 07:29:00 | 07:30:00 |
| 4 | J1 | STD | 4 | 07:44:00 | 07:45:00 |
| 5 | J1 | STE | 5 | 07:59:00 | 08:00:00 |
| 6 | J1 | STF | 6 | 08:15:00 | NULL |
| 7 | J2 | STA | 1 | NULL | 07:30:00 |
| 8 | J2 | STC | 2 | 07:59:00 | 08:00:00 |
| 9 | J2 | STF | 3 | 08:45:00 | NULL |
| 10 | J3 | STA | 1 | NULL | 08:00:00 |
| 11 | J3 | STB | 2 | 08:09:00 | 08:10:00 |
| 12 | J3 | STD | 3 | 08:44:00 | 08:45:00 |
| 13 | J3 | STE | 4 | 09:00:00 | NULL |
| 14 | J4 | STA | 1 | NULL | 08:30:00 |
| 15 | J4 | STD | 2 | 09:14:00 | 09:15:00 |
| 16 | J4 | STF | 3 | 09:45:00 | NULL |
| 17 | J5 | STF | 1 | NULL | 07:10:00 |
| 18 | J5 | STE | 2 | 07:24:00 | 07:25:00 |
| 19 | J5 | STD | 3 | 07:39:00 | 07:40:00 |
| 20 | J5 | STC | 4 | 07:54:00 | 07:55:00 |
| 21 | J5 | STB | 5 | 08:14:00 | 08:15:00 |
| 22 | J5 | STA | 6 | 08:25:00 | NULL |
| 23 | J6 | STF | 1 | NULL | 07:30:00 |
| 24 | J6 | STC | 2 | 08:14:00 | 08:15:00 |
| 25 | J6 | STA | 3 | 08:45:00 | NULL |
| 26 | J7 | STE | 1 | NULL | 08:00:00 |
| 27 | J7 | STD | 2 | 08:14:00 | 08:15:00 |
| 28 | J7 | STB | 3 | 08:49:00 | 08:50:00 |
| 29 | J7 | STA | 4 | 09:00:00 | NULL |
| 30 | J8 | STF | 1 | NULL | 08:20:00 |
| 31 | J8 | STD | 2 | 08:49:00 | 08:50:00 |
| 32 | J8 | STA | 3 | 09:35:00 | NULL |
+----+---------+---------+---------+----------+----------+
每个方向有四个行程（J1 到 J8）。
我需要能够回答以下问题：
哪些行程从 STB 到 STD（回答 J1 和 J3）但不包括相反方向的行程（J5 和 J7）？
哪些行程在 STC 停靠（回答 J1、J2、J5 和 J6）？
我试过子查询、自连接、创建临时 table 然后查询它，但我的头撞到了砖墙上。我什至不知道我的 table 的设计是否最优。
最后，这里是创建和填充 table 的 SQL：
CREATE TABLE `journeys` (
`id` int(11) NOT NULL,
`j_id` int(11) NOT NULL,
`journey` varchar(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `journeys` (`id`, `j_id`, `journey`) VALUES
(1, 1, 'J1'),
(2, 2, 'J2'),
(3, 3, 'J3'),
(4, 4, 'J4'),
(5, 5, 'J5'),
(6, 6, 'J6'),
(7, 7, 'J7'),
(8, 8, 'J8');
.
CREATE TABLE `stations` (
`id` int(11) NOT NULL,
`s_id` int(11) NOT NULL,
`station` varchar(3) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `stations` (`id`, `s_id`, `station`) VALUES
(1, 1, 'STA'),
(2, 2, 'STB'),
(3, 3, 'STC'),
(4, 4, 'STD'),
(5, 5, 'STE'),
(6, 6, 'STF');
.
CREATE TABLE `schedules` (
`id` int(11) NOT NULL,
`j_id` int(11) NOT NULL,
`s_id` int(11) NOT NULL,
`s_order` int(11) NOT NULL,
`a_time` time DEFAULT NULL,
`d_time` time DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `schedules` (`id`, `j_id`, `s_id`, `s_order`, `a_time`, `d_time`)
VALUES
(1, 1, 1, 1, NULL, '07:00:00'),
(2, 1, 2, 2, '07:09:00', '07:10:00'),
(3, 1, 3, 3, '07:29:00', '07:30:00'),
(4, 1, 4, 4, '07:44:00', '07:45:00'),
(5, 1, 5, 5, '07:59:00', '08:00:00'),
(6, 1, 6, 6, '08:15:00', NULL),
(7, 2, 1, 1, NULL, '07:30:00'),
(8, 2, 3, 2, '07:59:00', '08:00:00'),
(9, 2, 6, 3, '08:45:00', NULL),
(10, 3, 1, 1, NULL, '08:00:00'),
(11, 3, 2, 2, '08:09:00', '08:10:00'),
(12, 3, 4, 3, '08:44:00', '08:45:00'),
(13, 3, 5, 4, '09:00:00', NULL),
(14, 4, 1, 1, NULL, '08:30:00'),
(15, 4, 4, 2, '09:14:00', '09:15:00'),
(16, 4, 6, 3, '09:45:00', NULL),
(17, 5, 6, 1, NULL, '07:10:00'),
(18, 5, 5, 2, '07:24:00', '07:25:00'),
(19, 5, 4, 3, '07:39:00', '07:40:00'),
(20, 5, 3, 4, '07:54:00', '07:55:00'),
(21, 5, 2, 5, '08:14:00', '08:15:00'),
(22, 5, 1, 6, '08:25:00', NULL),
(23, 6, 6, 1, NULL, '07:30:00'),
(24, 6, 3, 2, '08:14:00', '08:15:00'),
(25, 6, 1, 3, '08:45:00', NULL),
(26, 7, 5, 1, NULL, '08:00:00'),
(27, 7, 4, 2, '08:14:00', '08:15:00'),
(28, 7, 2, 3, '08:49:00', '08:50:00'),
(29, 7, 1, 4, '09:00:00', NULL),
(30, 8, 6, 1, NULL, '08:20:00'),
(31, 8, 4, 2, '08:49:00', '08:50:00'),
(32, 8, 1, 3, '09:35:00', NULL);
我希望我已经提供了足够的信息以便有人能够提供帮助。
感谢您的时间和耐心等待。
*****更新*****
好的，所以我取得了一些进展。 运行 以下 SQL 在单独的段中（如果我 运行 一起出错）：
DROP TEMPORARY TABLE IF EXISTS tableSTART;
.
DROP TEMPORARY TABLE IF EXISTS tableEND;
.
CREATE TEMPORARY TABLE IF NOT EXISTS tableSTART AS
(
SELECT schedules.id, journeys.journey, stations.station, schedules.s_order,
schedules.a_time, schedules.d_time
FROM `schedules`
JOIN `journeys` ON schedules.j_id = journeys.j_id
JOIN `stations` ON schedules.s_id = stations.s_id
WHERE stations.station = "STB"
);
.
CREATE TEMPORARY TABLE IF NOT EXISTS tableEND AS
(
SELECT schedules.id, journeys.journey, stations.station, schedules.s_order,
schedules.a_time, schedules.d_time
FROM `schedules`
JOIN `journeys` ON schedules.j_id = journeys.j_id
JOIN `stations` ON schedules.s_id = stations.s_id
WHERE stations.station = "STE"
);
.
select ts.journey, ts.station startStn, ts.s_order startOrder, te.journey,
te.station endStn, te.s_order endOrder
from tableSTART ts
cross join tableEND te
这显示了旅程、起点 (STB) 和终点 (STE) 站以及起点站和终点站的车站顺序。我如何过滤它以仅留下开始顺序小于结束顺序的那些旅程（即从 STB 到 STE 并排除从 STE 到 STB 的旅程？
提前致谢。
从 STB 到 STD 有哪些行程？
我们想要这样的旅程：
- 在 STB 有一些预定的停留
- 有一些（其他）停止在 STD
- 在 STD 之前停在 STB
select j.journey
from journeys j
-- have some scheduled stop at STB
join schedules sc1 on sc1.j_id = j.id
join stations st1 on st1.id = sc1.s_id
and st1.station = 'STB'
-- have some (other) stop scheduled at STD
join schedules sc2 on sc2.j_id = j.id
join stations st2 on st2.id = sc2.s_id
and st2.station = 'STD'
-- stop at STB before STD
where sc1.s_order < sc2.s_order;
注意你也可以这样写：
select j.journey
from journeys j
join schedules sc1 on sc1.j_id = j.id
join stations st1 on st1.id = sc1.s_id
join schedules sc2 on sc2.j_id = j.id
join stations st2 on st2.id = sc2.s_id
where st1.station = 'STB'
and st2.station = 'STD'
and sc1.s_order < sc2.s_order;
（将条件放入内部联接的 on 与将它们放入 where 相同）
哪些旅程在 STC 停靠？
（可能是微不足道的，在上面之后）
select j.journey
from journeys j
join schedules sc on sc.j_id = j.id
join stations st on st.id = sc.s_id
where st.station = 'STC';
请注意，这正是您使用较少列和 where :)