Has many relation - destroy troubles

Rails
1

Hello, Rookie here … learning rails and enjoying it … having a
bit-o-trouble with has many in the following scenario:

class Party < ActiveRecord::Base
has_many :target_associations, :foreign_key => ‘source_party_id’,
:class_name => ‘PartyAssociation’,
:dependent => :destroy

has_many :source_associations, :foreign_key => ‘target_party_id’,
:class_name => ‘PartyAssociation’,
:dependent => :destroy
end

class PartyAssociation < ActiveRecord::Base
belongs_to :party, :foreign_key => “source_party_id”
belongs_to :party, :foreign_key => “target_party_id”
end

class CreateParties < ActiveRecord::Migration
def change
create_table :parties do |t|
t.timestamps
end
end
end

class CreatePartyAssociations < ActiveRecord::Migration
def change
create_table :party_associations, :id => false do |t|
t.integer :source_party_id
t.integer :target_party_id

  t.timestamps
end

end
end

This RSpec statement:
it “should destroy source associations” do
@party.destroy
end

Causes this ERROR MESSAGE:
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column:
party_associations.: DELETE FROM “party_associations” WHERE
“party_associations”."" = ?

What am I doing wrong that prevents active record from knowing how to
form the delete statement?

2

On 14 January 2012 01:43, Douglas B. [email protected] wrote:

       :dependent => :destroy

t.timestamps
end
end
end

class CreatePartyAssociations < ActiveRecord::Migration
def change
create_table :party_associations, :id => false do |t|

You should not have :id false, the table needs an id column. It is
generally only when you use has_and_belongs_to_many that you do not
require an id column

Colin

3

Uh … ended up changing things to use the Has Many Through association
… now it all works and looks like this:

#Created a parties table
class CreateParties < ActiveRecord::Migration
def change
create_table :parties do |t|
t.string :type

  t.timestamps
end

end
end

#created a join table to associate one party to another
class CreateAssociatedParties < ActiveRecord::Migration

def change
create_table :associated_parties do |t|
t.integer :association_type_id
t.integer :parent_id
t.integer :child_id
end
end

end

#With a Party class like this using hmt
class Party < ActiveRecord::Base

has_many :primary_associations, :foreign_key => ‘parent_id’,
:class_name => ‘AssociatedParty’,
:dependent => :destroy
has_many :children, :through => :primary_associations

has_many :secondary_associations, :foreign_key => ‘child_id’,
:class_name => ‘AssociatedParty’,
:dependent => :destroy
has_many :parents, :through => :secondary_associations

end

#And the join class like this
class AssociatedParty < ActiveRecord::Base

belongs_to :parent, :class_name => “Party”
belongs_to :child, :class_name => “Party”

end