Plugins - Foreign Key Associations
Add to favoritesForeign Key Associations is a plugin that automatically creates associations based on foreign-keys. The associations are created at runtime—ie. as your ActiveRecord models are loaded—so they will always be up-to-date.
For example, given a foreign-key from a customer_id column in an orders table to an id column in a customers table, the plugin creates:
Order.belongs_to :customer Customer.has_many :orders
If there is a uniqueness constraint—eg unique index—on a foreign-key column, then the plugin will creates a has_one instead of a has_many.
For example, given a foreign-key from an order_id column with a uniqueness constraint in an invoices table to an id column in an orders table, the plugin creates:
Invoice.belongs_to :order Order.has_one :invoice
Additionally, if there is a position column in the child table, the parent association will be created with an order clause.
For example, given a foreign-key from a order_id column in an order_lines table containing a position column, to an id column in a orders table, the plugin creates:
OrderLine.belongs_to :orders Order.has_many :lines, :order => :position
And finally, notice that in the previous example, the association name used for the Order.has_many is :lines and not :order_lines. More specifically, the plugin removes the prefix from has_many and has_one associations if the the name of parent class forms a proper prefix of the child class name.
The plugin fully supports and understands the following active-record configuration properties:
- config.active_record.pluralize_table_names
- config.active_record.table_name_prefix
- config.active_record.table_name_suffix
Dependencies
- RedHill on Rails Core (redhillonrails_core)
See Also
- Foreign Key Migrations (foreign_key_migrations).
http://www.redhillconsulting.com.au/rails_plugins.html
svn://rubyforge.org/var/svn/redhillonrails/trunk/vendor/plugins/foreign_key_associations
Rails' (MIT)
Misc. Enhancements
