Re: [Rails] Re: how to specify relationship between these models
On 19 March 2010 11:43, Tom Mac wrote: > why everything is stored in a single table That's called Single Table Inheritance (STI) > Can we store each items for say staff,director etc to > there own tables? Or Am I wrong? You're not wrong; you can do it with different tables if you want. Data modelling is done however is best for you. Sometimes you might start with STI, refactor to associations, and then refactor back to STI as your project requirements evolve. Problems may occur when, for instance, your Managers also need to have elements of the properties of Staff - you can't inherit from two base-classes, so you have to start looking at mixing-in modules instead, or of some other method of structuring your data to make it make sense. Also, what happens if you have someone who's a staff member of two offices (if that's possible for your organisation)? Can they have different roles in the different places? etc... Personally, I tend to keep "users" as a table for authentication-related info, and in my "people" table (I'd tend to avoid STI for people) I keep personal info, link to a user record, and assign a "role" which is used for handling permissions. I'd rather have lots of associations for data, because that's more flexible than one wide flat table (the likes of which STI generally leads to...) -- 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 rubyonrails-t...@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
[Rails] Re: how to specify relationship between these models
Hi Thanks for your reply. This I have already thought of. But one thing I can't understand is why everything is stored in a single table say users here? Can we store each items for say staff,director etc to there own tables? Or Am I wrong? Tom -- Posted via http://www.ruby-forum.com/. -- 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 rubyonrails-t...@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
[Rails] Re: how to specify relationship between these models
Let say you are having staff, directors and managers as part of your system, and their details will be in users table so let say we can build inheritance based relationship like below: Class User < ActiveRecord::Base end Class Staff < User end Class Director < User end Class Manager < User end users table: id type name email phone city state etc Now just you can create staff, directors as follows staff = Staff.create(:name=>"Tom Mac", :email=>"tom@xyz.com") So it will create one record in users table and mark the column type with "Staff". Hope it will solve your issue. Regards. T.Veeraa -- Posted via http://www.ruby-forum.com/. -- 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 rubyonrails-t...@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
