Rails Active Record

Active Record is Rails' Object-Relational Mapping (ORM) layer that provides a clean, intuitive interface for interacting with database records as Ruby objects. It handles model definitions, relationships between models, data validation, persistence, and complex queries through a declarative, expressive API.

When to Use This Skill

• Defining model relationships (has_many, belongs_to, polymorphic associations, through associations)
• Adding validations to ensure data integrity at the application level
• Building complex queries with scoping, eager loading, and joins
• Implementing inheritance patterns with single table inheritance (STI) or class table inheritance
• Optimizing database access patterns to prevent N+1 queries
• Working with callbacks for model lifecycle events
• Implementing soft deletes, auditing, and other advanced patterns
• Querying with conditions, aggregations, and complex WHERE clauses

Quick Start

Basic Model Definition