建立模型之间的构成关系

Question

i have a background about OOP

I know these

//association by

has_many
belongs_to

//aggregation by

composed_of

//Inheritance => STI & MTI

how i can implement a composition relationship ?

can i make it like

has_many, dependency: :destroy

Answer 1

You can use dependent: :destroy , as shown below:

 has_many model_name, dependent: :destroy

Here is an example:

class Author
  has_many :posts, dependent: :destroy
end

An Author can have many Posts . When the Author is destroyed all of its child posts are also destroyed.