Database table naming conventions in Ruby on Rails - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Pluralization of table names in Rails

In Rails, what is the conventional way to name database tables for models?

A Use plural form of the model name, e.g., 'users' for User model

B Use singular form of the model name, e.g., 'user' for User model

C Use uppercase model name as table name, e.g., 'User' for User model

D Use camelCase model name as table name, e.g., 'userProfile' for UserProfile model

💡 Hint

Think about how Rails automatically maps models to tables.

Rails uses pluralized lowercase table names by convention. For example, the User model maps to the 'users' table.

🧠 Conceptual

intermediate

Naming join tables for many-to-many relationships

How should you name a join table for a many-to-many relationship between models 'Author' and 'Book' in Rails?

A author_book

B authors_books

C books_authors

D authorBooks

💡 Hint

Rails expects join tables to be named alphabetically and pluralized.

Join tables in Rails are named by combining the pluralized model names in alphabetical order separated by an underscore. So 'authors_books' is correct.

❓ query_result

advanced

Effect of incorrect table naming on ActiveRecord queries

Given a Rails model named 'ProductCategory' but the database table is named 'productcategory', what will happen when you run ProductCategory.all?

A It will return all records from the 'productcategory' table without error

B It will return an empty array because no matching table is found

C It will raise an ActiveRecord::StatementInvalid error because the table name does not match the expected 'product_categories'

D It will automatically find the 'productcategory' table ignoring naming conventions

💡 Hint

Rails expects table names to be plural and underscored by default.

ActiveRecord expects the table name to be the pluralized, underscored version of the model name. If the table name is incorrect, it raises an error.

❓ schema

advanced

Custom table name declaration in Rails model

How can you specify a custom table name 'inventory_items' for a Rails model named 'Item'?

A

class Item < ApplicationRecord
  self.table_name = 'inventory_items'
end

B

class Item < ApplicationRecord
  table_name = 'inventory_items'
end

C

class Item < ApplicationRecord
  set_table_name 'inventory_items'
end

D

class Item < ApplicationRecord
  @table_name = 'inventory_items'
end

💡 Hint

Look for the correct syntax to override the table name in Rails models.

The correct way to set a custom table name is by assigning to self.table_name inside the model class.

❓ optimization

expert

Optimizing queries with table naming and indexing

You have a large Rails app with a table named 'user_sessions' storing millions of records. Which naming and indexing strategy helps optimize queries filtering by 'user_id'?

A Rename the table to 'user_sessions_data' and add a composite index on 'user_id' and 'session_token'

B Rename the table to 'usersessions' and add a unique index on 'user_id'

C Keep the table named 'user_sessions' and do not add any indexes

D Keep the table named 'user_sessions' and add an index on the 'user_id' column

💡 Hint

Think about Rails conventions and indexing for query speed.

Keeping the conventional table name and adding an index on the frequently queried column improves query performance without breaking conventions.