我正在尝试设计一个数据库来存储 300 条不同公交路线的时间表,每条路线在周一至周五、周六和周日都有不同的停靠点和不同的时间。我已经将每条路线的巴士出发时间表示如下,我不确定我是否应该在表中包含空值,这看起来可以吗?
route,Num,Day, t1, t2, t3, t4 t5 t6 t7 t8 t9 t10
117, 1, Monday, 9:00, 9:30, 10:50, 12:00, 14:00 18:00 19:00 null null null
117, 2, Monday, 9:03, 9:33, 10:53, 12:03, 14:03 18:03 19:03 null null null
117, 3, Monday, 9:06, 9:36, 10:56, 12:06, 14:06 18:06 19:06 null null null
117, 4, Monday, 9:09, 9:39, 10:59, 12:09, 14:09 18:09 19:09 null null null
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117, 20, Monday, 9:39, 10.09, 11:39, 12:39, 14:39 18:39 19:39 null null null
119, 1, Monday, 9:00, 9:30, 10:50, 12:00, 14:00 18:00 19:00 20:00 21:00 22:00
119, 2, Monday, 9:03, 9:33, 10:53, 12:03, 14:03 18:03 19:03 20:03 21:03 22:03
119, 3, Monday, 9:06, 9:36, 10:56, 12:06, 14:06 18:06 19:06 20:06 21:06 22:06
119, 4, Monday, 9:09, 9:39, 10:59, 12:09, 14:09 18:09 19:09 20:09 21:09 22:09
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119, 37, Monday, 9:49, 9:59, 11:59, 12:59, 14:59 18:59 19:59 20:59 21:59 22:59
139, 1, Sunday, 9:00, 9:30, 20:00 21:00 22:00 null null null null null
139, 2, Sunday, 9:03, 9:33, 20:03 21:03 22:03 null null null null null
139, 3, Sunday, 9:06, 9:36, 20:06 21:06 22:06 null null null null null
139, 4, Sunday, 9:09, 9:39, 20:09 21:09 22:09 null null null null null
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139, 20, Sunday, 9:49, 9:59, 20:59 21:59 22:59 null null null null null