Rails - Dec 2005 - ActiveRecord: manually setting :id

Hey everyone,

I''m having a problem with ActiveRecord (outside of Rails) where it
doesn''t allow me to set the value of the :id column.  Since
you''re
probably not normally supposed to fiddle with the primary key, I''m
guessing that this isn''t a bug, but is intentional.  Is there any way
to override it?

The reason I need this is that I''m making a library that loads data
from a relational-like XML format into various other
databases/formats.  Since the primary keys were already established in
the application that made the XML file, I need to be able to link the
records using those ids, and not the auto-increment values that MySQL
(or any other DB) assigns.

I''d rather not use raw SQL to do this so that I can get this to work
with all of the DBs that AR supports out of the box.  Any ideas?

Thanks,
Andrew

Hi,

Maybe this document will helps you; 
http://ar.rubyonrails.com/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html

Especially these parts;

Rename the primary key column

 create_table(:objects, :primary_key => ''guid'') do |t|
   t.column :name, :string, :limit => 80
 end

generates:

 CREATE TABLE objects (
   guid int(11) DEFAULT NULL auto_increment PRIMARY KEY,
   name varchar(80)
 )

But i never use active record out side of rail. But also i think that 
the concept will be same. You can find more detailed infi in the source 
code of active record. it has a well documanted.


Andrew O''Brien wrote:
> Hey everyone,
> 
> I''m having a problem with ActiveRecord (outside of Rails) where it
> doesn''t allow me to set the value of the :id column.  Since
you''re
> probably not normally supposed to fiddle with the primary key, I''m
> guessing that this isn''t a bug, but is intentional.  Is there any
way
> to override it?
> 
> The reason I need this is that I''m making a library that loads
data
> from a relational-like XML format into various other
> databases/formats.  Since the primary keys were already established in
> the application that made the XML file, I need to be able to link the
> records using those ids, and not the auto-increment values that MySQL
> (or any other DB) assigns.
> 
> I''d rather not use raw SQL to do this so that I can get this to
work
> with all of the DBs that AR supports out of the box.  Any ideas?
> 
> Thanks,
> Andrew

-- 
Posted via http://www.ruby-forum.com/.

And if u ask override it when you are using Active record in classes 
this will be helpful;

class Child < ActiveRecord::Base
belongs_to :parents , :primary_key => "name"
end

-- 
Posted via http://www.ruby-forum.com/.

Andrew O''Brien wrote:
> I''m having a problem with ActiveRecord (outside of Rails) where it
> doesn''t allow me to set the value of the :id column.  Since
you''re
> probably not normally supposed to fiddle with the primary key, I''m
> guessing that this isn''t a bug, but is intentional.  Is there any
way
> to override it?
Yes, if you mean that "Model.new(:id =>
''foo'').save" doesn''t work.  Try
"Model.new { |m| m.id = 42 }", that seems to work for me.

-- Steve