ActiveRecord Basics
Models, migrations, CRUD operations, validations, callbacks, scopes
1What is ActiveRecord in the context of Ruby on Rails?
What is ActiveRecord in the context of Ruby on Rails?
回答
ActiveRecord is the ORM (Object-Relational Mapping) component of Rails that represents the M (Model) in the MVC pattern. It allows manipulating database data as Ruby objects, establishing a correspondence between SQL tables and Ruby classes, and between columns and object attributes.
2According to Rails conventions, what is the table name associated with a model named Article?
According to Rails conventions, what is the table name associated with a model named Article?
回答
Rails uses a naming convention where the model name is singular and in CamelCase while the table name is plural and in snake_case. Thus, an Article model automatically corresponds to a table named articles. This convention allows Rails to infer associations without explicit configuration.
3Which Rails command creates a new model with a migration?
Which Rails command creates a new model with a migration?
回答
The rails generate model command (or rails g model for short) simultaneously creates the model file in app/models, the corresponding migration file in db/migrate, and the test files. This ensures that the database structure and the Ruby model remain synchronized from the start.
What is a migration in Rails?
Which command runs all pending migrations?
+22 面接問題