Marnen Thank you for taking the trouble to reply.
On Aug 25, 5:40 pm, Marnen Laibow-Koser <[email protected]> wrote: > Owain wrote: > > That could > > be done by serializing the Set object but then I lose the ability of > > database queries (in particular indexing performance gains) to do > > something like, show me all of the bookings of the resources [11, 14, > > 16], which is of course another set. > > > But a relational database is just set theory in disguise I hear you > > say! But surely my webservice does not need to have a table called > > Resource with a column called application_id and a column called > > resource_id (and the extra id created by Active Record). > > No, I think it does. You *want* each resource to be a separate object > in your application, and you *want* each resource to be a separate > object in your DB, I think. That will give you the queries you mention > above, and keep each resource individually addressable. > > Why do you think you don't need to do this? It seems like the best way > to me. The thing is that there is no other attribute of the model needed by the booking engine other than 'id'. So imagine that the resources being booked were coloured pencils. A booking would be for red, blue and green. There is no need to have another table for colours. The availability object would hold all of the available colours. I don't really see the point of the having a table with the following rows: application_id, resource pencil_booker, red pencil_booker, orange pencil_booker, yellow pencil_booker, green pencil_booker, blue pencil_booker, indigo pencil_booker, violet pencil_booker, dayglow_yellow And maybe this is the difference, this table DOES exist in another form in the RoR application that calls the webservice. So the calling service knows that orange has an id of 1234567 and the booking engine sees that as a resource available and for booking. The booking service is not domain specific, it just implements some booking logic. Taking a real example, using our traditional approach I would need to set up a the resource table with a row for every day that is made available (using its Julian form as an id) with a HABTM relationship through an associative entity table just to be able to be able to find all bookings for a particular day or week? A sledgehammer to crack a nut? O. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
