Rails - Mar 2010 - Relationship between Customer, Person, Employee, User entity

Hello Friends,

I am trying to define relationship between real-world entities in my
application.... But I am feel, I am over-representing it a little and
hence would like your opinion.

class User < ActiveRecord::Base
  has_and_belongs_to_many :user_groups

  attr_accessible :username, :email, :password, :password_confirmation

end

class Customer < User
  has_many :orders

  belongs_to :person
end

class Employee < User
  belongs_to :person

end

class Person < ActiveRecord::Base
  has_many :addresses
end


Should I merge User and Person Models? Basically user has only login
information while Person has details like first_name, last_name, address
and so on....

Also, should Customer and Employee inherit from Person or User? Trying
to normalize stuff but dont want to over-normalize it too..

Thank you.
-- 
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-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

On 29 March 2010 10:43, Paritian Thakkar
<lists-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org>
wrote:
> Hello Friends,
>
> I am trying to define relationship between real-world entities in my
> application.... But I am feel, I am over-representing it a little and
> hence would like your opinion.
>
> class User < ActiveRecord::Base
>  has_and_belongs_to_many :user_groups
>
>  attr_accessible :username, :email, :password, :password_confirmation
>
> end
>
> class Customer < User
>  has_many :orders
>
>  belongs_to :person
> end
>
> class Employee < User
>  belongs_to :person
>
> end
>
> class Person < ActiveRecord::Base
>  has_many :addresses
> end
>
>
> Should I merge User and Person Models? Basically user has only login
> information while Person has details like first_name, last_name, address
> and so on....
Yes, why complicate matters.

Have you considered that a user might be both a customer and an
employee?  Your model would preclude that I think.  Are you sure it
would not be better just to have the user model who can be either or
both just by attribute contents?

Colin
>
> Also, should Customer and Employee inherit from Person or User? Trying
> to normalize stuff but dont want to over-normalize it too..
>
> Thank you.
> --
> 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-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
> To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe@googlegroups.com.
> For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.
>
>
-- 
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-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

I think the differences between Customer and Employee is Role, when you
assign a ''customer'' role, he is a customer.

So you could use Role to distinguish different person, and a person may have
many roles

class User < ActiveRecord::Base
  has_many :roles
  has_many :addresses
end

On Mon, Mar 29, 2010 at 5:43 PM, Paritian Thakkar
<lists-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org>wrote:
> Hello Friends,
>
> I am trying to define relationship between real-world entities in my
> application.... But I am feel, I am over-representing it a little and
> hence would like your opinion.
>
> class User < ActiveRecord::Base
>  has_and_belongs_to_many :user_groups
>
>  attr_accessible :username, :email, :password, :password_confirmation
>
> end
>
> class Customer < User
>  has_many :orders
>
>  belongs_to :person
> end
>
> class Employee < User
>  belongs_to :person
>
> end
>
> class Person < ActiveRecord::Base
>  has_many :addresses
> end
>
>
> Should I merge User and Person Models? Basically user has only login
> information while Person has details like first_name, last_name, address
> and so on....
>
> Also, should Customer and Employee inherit from Person or User? Trying
> to normalize stuff but dont want to over-normalize it too..
>
> Thank you.
> --
> 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-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
> To unsubscribe from this group, send email to
>
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org<rubyonrails-talk%2Bunsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org>
> .
> For more options, visit this group at
> http://groups.google.com/group/rubyonrails-talk?hl=en.
>
>
-- 
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-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

Colin Law wrote:
> Yes, why complicate matters.
> 
> Have you considered that a user might be both a customer and an
> employee?  Your model would preclude that I think.  Are you sure it
> would not be better just to have the user model who can be either or
> both just by attribute contents?
> 
> Colin
Valid point :)

I do not want to combine Customer and Employee tables because they have 
quite different attributes...

Employee has department, manager, roles etc...
Customer has current status, credit card info etc.. bunch of stuff I 
will collect on registration.. If I combine them, the resulting table 
will be a little too huge..


-- 
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-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

On 29 March 2010 11:23, Paritian Thakkar
<lists-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org>
wrote:
> Colin Law wrote:
>
>> Yes, why complicate matters.
>>
>> Have you considered that a user might be both a customer and an
>> employee?  Your model would preclude that I think.  Are you sure it
>> would not be better just to have the user model who can be either or
>> both just by attribute contents?
>>
>> Colin
>
> Valid point :)
>
> I do not want to combine Customer and Employee tables because they have
> quite different attributes...
>
> Employee has department, manager, roles etc...
> Customer has current status, credit card info etc.. bunch of stuff I
> will collect on registration.. If I combine them, the resulting table
> will be a little too huge..
Assuming you plan to use STI for the tables then the table contains
all the attributes for both anyway.  Presumably most of the stuff is
varchar which are variable length fields. so consume very little
space.  How many million customers are you expecting so that db size
becomes a factor? :)

Colin

-- 
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-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.