Agent Skills: ActiveRecord Query Patterns

Complete guide to ActiveRecord query optimization, associations, scopes, and PostgreSQL-specific patterns. Use when: (1) Writing database queries, (2) Designing model associations, (3) Creating migrations, (4) Optimizing query performance, (5) Debugging N+1 queries and GROUP BY errors. Trigger keywords: database, models, associations, validations, queries, ActiveRecord, scopes, migrations, N+1, PostgreSQL, indexes, eager loading