Rails - May 2006 - Question about one-to-many-to-many

Guys,

I''ve set up a 1-M-M relationship between 3 tables/models.  I
can''t get
cascading deletes (haven''t tried updates yet) to work when the master 
record is deleted.  I''m using MySQL 4.1.x, and the error message is:

Mysql::Error: #23000Cannot delete or update a parent row: a foreign key 
constraint fails: DELETE FROM contact_addresses WHERE (contact_id = 1).

Is this something that''s not supported by MySQL?  Or might I have setup
my models (has_many, belongs_to, etc.) incorrectly?

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Oops, forgot to mention - the error above is referring to the 1st M 
table.  What I believe is obviously happening is that the master record 
in the 1st M table is being deleted, but it can''t because there are 
child records still in the 2nd M table.

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What do your relationships look like?

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Adam,

Logically speaking, a contact can have multiple addresses, and each 
address can have multiple phone numbers:

Contact (master):

  has_many :contact_addresses, :dependent => :delete_all

ContactAddress (detail 1):

  belongs_to :contact
  has_many   :addresses_phones, :dependent => :delete_all
  has_many   :contact_phones,   :through => :addresses_phones

ContactPhone (detail 2):

  belongs_to :contact_addresses
  has_many :addresses_phones,  :dependent => :delete_all
  has_many :contact_addresses, :through => :addresses_phones

The addresses_phones table (which links addresses and phones) is not in 
the model, and simply contains contact_address_id and a contact_phone_id 
columns.

I''m wondering if I need to write a line or 2 of code that first deletes
the phone records so that Rails can then delete the address and contact 
records.

Here''s the inspiration for all of the above:

http://tinyurl.com/kk5gt

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