Rails - Jun 2007 - Importing flat CSV into two tables and maintaining a relationship

Hello,


I''m new to Ruby on Rails and I''ve been really enjoying the
framework.
I have recently hit a wall that I can''t seem to get around.
I''ve
searched to web and haven''t found an answer(and my agile development
with rails book hasn''t arrived).....


My problem:  I have a CSV file that has information about  recreation
programs, and the buildings that each program is housed in.  It is in
a one line format.


So,


Building name | Location | Program name | Description of program |
Time |


Buildings have many programs, but programs only have one building.

I need to import this CSV into a mysql database.  I can do this using
migrations and FasterCSV.  There are duplicate entries for buildings,
and I only want each building entered into the database once, which I
could use validates uniqueness to ensure.

The wall I''ve encountered is how do I maintain the relationship
between programs and buildings throughout this import process?

Ie I want to be able to list the programs in each building...

Many Thanks and apologies if there is a very obvious solution that I
am missing,

Jay


--~--~---------~--~----~------------~-------~--~----~
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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

On Jun 25, 2007, at 4:27 PM, Jay wrote:
> Hello,
>
> I''m new to Ruby on Rails and I''ve been really enjoying
the framework.
> I have recently hit a wall that I can''t seem to get around.
I''ve
> searched to web and haven''t found an answer(and my agile
development
> with rails book hasn''t arrived).....
>
> My problem:  I have a CSV file that has information about  recreation
> programs, and the buildings that each program is housed in.  It is in
> a one line format.
>
> So,
>
> Building name | Location | Program name | Description of program |  
> Time |
>
> Buildings have many programs, but programs only have one building.
>
> I need to import this CSV into a mysql database.  I can do this using
> migrations and FasterCSV.  There are duplicate entries for buildings,
> and I only want each building entered into the database once, which I
> could use validates uniqueness to ensure.
>
> The wall I''ve encountered is how do I maintain the relationship
> between programs and buildings throughout this import process?
>
> Ie I want to be able to list the programs in each building...
>
> Many Thanks and apologies if there is a very obvious solution that I
> am missing,
>
> Jay
Use:

   current_building = Building.find_or_create_by_name(bldg_name)

If you need to do something differently when the Building was created  
(like setup more attributes), you can:

   # new_record? is false on create, but nil on find
   unless current_building.new_record?.nil?
     ...
   end

Then I assume you have something like:

   current_building.programs.create(...)

or:

   new_program.building = current_building

when you create the new program from the CSV data.

-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob-xa9cJyRlE0mWcWVYNo9pwxS2lgjeYSpx@public.gmane.org