Ruby on Rails 6 Essential Training: Models and Associations

Speed up and improve your development of full-featured web applications. Explore built-in features of models and associations in Ruby on Rails and apply these to a sample project.

Introduction

• Let ActiveRecord objects manage your data
• What you should know
• Using the exercise files on GitHub

1. Smarter Models

• Non-database attributes
• Smart models by design
• More ActiveRecord query methods
• Query data selection
• Named scopes
• Challenge: Named scopes
• Solution: Named scopes

2. Data Validations

• Overview of validation methods
• Write validations
• Use the multipurpose validates method
• Write custom validations
• How to skip validations
• Challenge: Validations
• Solution: Validations

3. ActiveRecord Callbacks

• Overview of callbacks
• Use callbacks to automate actions
• Execute callbacks conditionally
• How to skip callbacks
• Challenge: Callbacks
• Solution: Callbacks

4. ActiveRecord Associations

• Work with associations
• Validate presence with belongs_to
• Destroy dependent-related records
• Has and belongs to many relationships
• Rich join associations
• Traversing a rich join association
• Joining tables during queries

Conclusion

• Next steps