self refrencing many to one implementation

rubyonrails-talk
1

hello, i have database for dynamic website in which i need to store information about each menu and its relationship with other menu. it is obvious that each menu can have several submenu but each submenu must belong to one and ony one menu. so database goes like this

Pk_Content_id=>integer title =>integer, it is name of menu Image_path=>string, path of image Content_text=> text contained on click of every menu or description fK_parent_content_id => integer , THIS LINKS BACK TO pk_content_id ,as is a foreign key

what i want is to relate pk_content_id and fk_parent_content_id (which are in same table)

how to accomplish such self refrencing many to one relation???

m extreme beginner in rails please be more descriptive.

just to mention pk- represents primary key so is unique while fk is foreign key and is not unique, combinaly forms one to many relation

thanks in advance

2

The term you're looking for is "self referential" - very handy when Authors have Readers, or Employees have Managers...

You'll find lots of tutorials online, but essentially you set it up thus:

# Menu model has_many :children, :class_name => "Menu", :foreign_key => "parent_content_id" # those 'pk/fk' prefixes are not really good from the Rails conventions belongs_to :parent, , :class_name => "Menu"

But you might find that one of the "nesting" algorithms suits your need better - seeing as it seems you might be constantly recurring down the menus, "awesome_nested_set" might be worth a look.

Hope this helps put you on track.