This article will discuss Single Table Inheritance in Ruby on Rails.
Often there are situations where models need to share a single table in the database. For example, building a salon application with a HairDresser model and a BeardDresser model. Separate database tables for the two models aren’t necessary because they share the same attributes - name, gender, age, salary, etc. Fortunately, they can share the same table using STI(Single Table Inheritance). Here is how to implement it.
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| rails new single-table-inheritance
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| rails generate model Expert name gender salary type
rails db:create db:migrate
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| # app/models/beard_dresser.rb
class BeardDresser < Expert
end
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| # app/models/hair_dresser.rb
class HairDresser < Expert
end
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| HairDresser.create(name: "John", gender: "male", salary: "10000")
BeardDresser.create(name: "Mike", gender: "male", salary: "9000")
HairDresser.count
=> 1
BeardDresser.count
=> 1
Expert.count
=> 2
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There you have it! Now you know how models can share a table in a database.