model

rubyonrails-talk
1

I have two tables. They are Service Desk and Incident.

I have to relate one of my service desk records with one or more service desk record(s) and/or one or more incident record(s). Hence the result of my search will both service desk records and/or incident records.

MY PROBLEM IS WHAT SHOULD BE THE TABLE STRUCTURE TO STORE THIS RESULT INCLUDING THE TYPE OF IT(ie WHETHER IT IS SERVICE DESK OR INCIDENT RECORD)

Thanks Sijo

2

One, you can do just as you say and "include the type". Create a 'type' column in each table with either an integer or you can place a string of "Service Desk" or "Incident"

Also what i would do is, I am positive you have a record or ticket number or something like that. I would place a 'SD' or 'IN' in front of the number to so you can tell what kind of record it is. If you have the same columns in each table then you can combine all the records in one table and just have a Ticket or Record table.

For example - SD1234 or IN4567

Hope this helps.... JB

3

Use a polymorphic association. It's polymorphic in the sense that it can associate to any other object in the system. You accomplish this by adding a compound foreign key -- one column gives the name of the class and the other gives the id of the instance. Your models would look something like this:

class ServiceDesk   has_many :serviceables, :polymorphic=>true   belongs_to :service_desk, :as=>:serviceable

  ... end

class Incident   belongs_to :service_desk, :as=>:serviceable

  ... end

With that...   @service_desk = ServiceDesk.find(1)   @service_desk.serviceables <= a collection of ServiceDesk and Incident objects (actually a proxy...)

Your migration probably looks like this:

def self.up   add_column :service_desks, :serviceable_type, :string   add_column :service_desks, :serviceable_id, :integer end

4

Hi

Thanks for your reply

Sijo

5

Can u Please evaluate the following as a solution

public def get_related_record_model   "ServiceDesk" end

in the SericeDesk and

public def get_related_record_model   "Incident" end

in Incident model

Then to store my result a table service_desk_related_records

6

That's essentially what the polymorphic does for you, with the bonus that "rails magic" takes care of all the coding for you. You only have to change "related_record_model" to "related_record_type" and your work is done.

By the way, you don't need a method to render out the name of the class. Use class.name