Declares a belongs to relationship.

This will add the following methods:

• association returns the associated object (or nil);
• association= assigns the associated object, assigning the foreign key;
• build_association builds the associated object, assigning the foreign key if the parent record is persisted, or delaying it to when the new record is saved;
• create_association creates the associated object, assigning the foreign key, granted that validation passed on the associated object;
• create_association! same as create_association but raises a Rome::RecordNotSaved exception when validation fails;
• reload_association to reload the associated object.

For example a Book class declares belongs_to :author which will add:

• Book#author (similar to Author.find(author_id))
• Book#author=(author) (similar to book.author_id = author.id)
• Book#build_author (similar to book.author = Author.new)
• Book#create_author (similar to book.author = Author.create)
• Book#create_author! (similar to book.author = Author.create!)
• Book#reload_author (force reload book.author)

Options

• class_name overrides the association class name (inferred as name.camelcase by default);
• foreign_key overrides the foreign key on the association (inferred as name + "_id" by default);
• autosave can be either:
  • nil (default) to only save newly built associations when the parent record is saved,
  • true to always save the associations (new or already persisted),
  • false to never save the associations automatically.
• dependent can be either:
  • :delete to delete the associated record in SQL,
  • :destroy to call #destroy on the associated object.

Declares a has many relationship.

This will add the following methods:

• associations returns a Relation(T);
• associations= assigns the associated objects, assigning the associations' foreign key, then saving the associations; permanently deletes the previously associated objects;

For example an Account class declares has_many :sellers which will add:

• Account#sellers
• Account#sellers=(sellers)

Options

• class_name overrides the association class name (inferred as name.singularize.camelcase by default);
• foreign_key overrides the foreign key for the association (inferred as the name of this class + "_id" by default);
• autosave can be either:
  • nil (default) to only save newly built associations when the parent record is saved,
  • true to always save the associations (new or already persisted),
  • false to never save the associations automatically.
• dependent can be either:
  • :nullify (default) to set the foreign key to nil in SQL,
  • :delete to delete the associated records in SQL,
  • :destroy to call #destroy on each associated objects.

Declares a has one relationship.

This will add the following methods:

• association returns the associated object (or nil).
• association= assigns the associated object, assigning the association's foreign key, then saving the association; permanently deletes the previously associated object;
• reload_association to reload the associated object.

For example an Account class declares has_one :supplier which will add:

• Account#supplier (similar to Supplier.find_by(account_id: account.id))
• Account#supplier=(supplier) (similar to supplier.account_id = account.id)
• Account#build_supplier
• Account#create_supplier
• Account#create_supplier!
• Account#reload_supplier

Options

• class_name overrides the association class name (inferred as name.camelcase by default);
• foreign_key overrides the foreign key for the association (inferred as the name of this class + "_id" by default);
• autosave can be either:
  • nil (default) to only save newly built associations when the parent record is saved,
  • true to always save the associations (new or already persisted),
  • false to never save the associations automatically.
• dependent can be either:
  • :nullify (default) to set the foreign key to nil in SQL,
  • :delete to delete the associated record in SQL,
  • :destroy to call #destroy on the associated object.