Steps for creating one to many relationship with SQL database in Rails

One to Many Relationship

1- Decide which one is the “parent” and which one is the “child”. So the parent has_many children
2- If you are using SQL database add a column to the child ActiveRecord model named parent_id
3- In the parent ActiveRecord model add has_many :children (notice we used plural in here)
4- In the child ActiveRecord model add belongs_to :parent (notice we used singular in here)
5- (optional) Change the child controller to be nested from the parent’s controller in order to re-use methods (mostly for before_filter) by:
    a- Makes the routes for the child  controller nested inside the “show” action of parent controller
    b- Make the child controller inherit from the parent controller.
    c- Setup filters as needed
    d- Change URLs relating to child controller around your app.