ruby script/plugin install svn://rubyforge.org/var/svn/redhillonrails/trunk/vendor/plugins/foreign_key_associations

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

The plugin also supports the creation of has_and_belongs_to_many associations.

For example, given the tables product_product_categories with foreign-keys to both the product and product_categories tables, the plugin creates:

Product.has_and_belongs_to_many :categories
ProductCategory.has_and_belongs_to_many :products

And finally, notice that in one of the previous examples, 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

There is currently no advanced documentation for this plugin.