On Sun, Oct 12, 2014 at 6:54 PM, Colin Law <clan...@gmail.com> wrote: > The first point is that you should only add rows as seats are booked, > use that fact that there is no row to indicate that there is no > booking.
> Secondly, what is the date? Is that the date of the journey or the > date of the booking? I don't understand why you have multiplied the > number of trains by 20 days. If it is the date of the journey then > consider having a Journeys table which is a particular train on a > particular day. It's the date of the journey. I once thought about this method, the problem is I don't know how to implement it in rails. In Rails tutorials and guidelines, there is a model file in app/model directory for every table. If I need to create new journey tables, what's the model files and migration files look like?(Or I don't need them any more?) > Thirdly I don't understand why you have 20 factorial for the city > combinations. Is it not true that if a seat is booked from station 1 > to station 3 then that implies a booking 1 to 2 and 2 to 3? In which > case you do not separate rows for bookings 1 to 2, 2 to 3, and 1 to 3. According to your first and third point, It's because my design is different. In my design one booking might indicates more than one row. A row just means the state of a seat. So, if a seat is booked from station 1 to station 3, then rows representing 1->3, 1->2, 2->3, 1->4, 1->5.... all need to change. I do it in this way because I have another table representing the number of left seats, and I think it's easier to update this table in my way(in this case, the number of leaf seats from 1->3, 1->2, 2->3.... decreases by one). Thank you for your suggestion! I'll dig it deeper and reveal my concerns. -- Best Regards -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArpqTg%2B9ot_bTLAB8jyse7JW9wT%3DMCaN0gArogHgKUB6yg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
