每隔一天选择巴士行驶方向 - Select every alternate days for selecting bus journey direction

我正在做一个公交车票预订系统。在这里，我为所有路线制作了表格，并在表格中添加了bus_number,fare等字段。现在我们的公共汽车每隔一天运行一次，反之亦然，即如果一辆公共汽车在2011年12月21日从X到Y运行，同一辆公共汽车将在下一个日期从Y到X运行。那么我怎么知道公交车的方向呢?如果我为每个公共汽车服务提供商制作表格，并添加公共汽车号码，为日期添加像"to"这样的标识符，我认为就有可能知道接下来所有天的状态。我不知道这是不是一个好主意，所以请帮助我。

如果不知道现有表的确切细节，就很难提供确定的解决方案。无论如何，这里有一个建议，教你如何把公共汽车的站点和票价记下来:

CREATE TABLE `bus` (
  `id` int unsigned not null primary key auto_increment,
  `bus_number` varchar(55) not null,
   UNIQUE KEY `busUidx1` (`bus_number`)
) ENGINE=InnoDB;
CREATE TABLE `bus_stop` (
  `id` int unsigned not null primary key auto_increment,
  `stop_description` varchar(250) not null,
  UNIQUE KEY `bus_stopUidx1` (`stop_description`)
) ENGINE=InnoDB;
CREATE TABLE `bus_route` (
  `id` int unsigned not null primary key auto_increment,
  `bus_id` int unsigned not null,
  `route_date` date not null,
  `bus_start_stop_id` int unsigned not null,
  `bus_end_stop_id` int unsigned not null,
  `fare` decimal (10,2) not null,
   UNIQUE KEY `bus_stopUidx1` (`bus_id`,`route_date`),
CONSTRAINT `fk_bus_route_bus_fk1` FOREIGN KEY (`bus_id`) REFERENCES `bus` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `fk_bus_route_stop_fk1` FOREIGN KEY (`bus_start_stop_id`) REFERENCES `bus_stop` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `fk_bus_route_stop_fk2` FOREIGN KEY (`bus_end_stop_id`) REFERENCES `bus_stop` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB;

使用此模型，您应该能够存储给定日期的公共汽车列表(在bus表中)，所有可能的站点列表(在bus_stop表中)和公共汽车路线。它还允许你灵活地打破"公共汽车从X> Y出发，然后总是从Y> X返回"的规则，如果我过去乘坐过的公共汽车是什么，可能会证明是有用的;-)

编辑

下面是一些示例数据，试图进一步说明我的答案:

insert into bus (bus_number) values ('Red Bus 1');
insert into bus (bus_number) values ('Red Bus 2');
insert into bus (bus_number) values ('Yellow Bus 1');
insert into bus (bus_number) values ('Yellow Bus 2');
insert into bus_stop (stop_description) values ('Stop 1');
insert into bus_stop (stop_description) values ('Stop 2');
insert into bus_stop (stop_description) values ('Stop 3');
insert into bus_stop (stop_description) values ('Stop 4');
insert into bus_route (bus_id,route_date,bus_start_stop_id,bus_end_stop_id,fare)
values (
(select id from bus where bus_number = 'Red Bus 1'),
'2011-12-11',
(select id from bus_stop where stop_description = 'Stop 1'),
(select id from bus_stop where stop_description = 'Stop 2'),
3.45);
insert into bus_route (bus_id,route_date,bus_start_stop_id,bus_end_stop_id,fare)
values (
(select id from bus where bus_number = 'Red Bus 1'),
'2011-12-12',
(select id from bus_stop where stop_description = 'Stop 2'),
(select id from bus_stop where stop_description = 'Stop 1'),
3.45);
insert into bus_route (bus_id,route_date,bus_start_stop_id,bus_end_stop_id,fare)
values (
(select id from bus where bus_number = 'Yellow Bus 1'),
'2011-12-11',
(select id from bus_stop where stop_description = 'Stop 3'),
(select id from bus_stop where stop_description = 'Stop 4'),
1.95);
insert into bus_route (bus_id,route_date,bus_start_stop_id,bus_end_stop_id,fare)
values (
(select id from bus where bus_number = 'Yellow Bus 1'),
'2011-12-12',
(select id from bus_stop where stop_description = 'Stop 4'),
(select id from bus_stop where stop_description = 'Stop 3'),
1.95);

最后是一个连接表的查询:

select b.bus_number,
       br.route_date,
       bs.stop_description as start,
       be.stop_description as end,
       br.fare
from bus_route br
inner join bus b on b.id = br.bus_id
inner join bus_stop bs on bs.id = br.bus_start_stop_id
inner join bus_stop be on be.id = br.bus_end_stop_id;