# Rails Models

> ActiveRecord patterns, migrations, validations, callbacks, associations

- **Type:** Skill
- **Install:** `agentstack add skill-shoebtamboli-rails-claude-skills-rails-models`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Shoebtamboli](https://agentstack.voostack.com/s/shoebtamboli)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Shoebtamboli](https://github.com/Shoebtamboli)
- **Source:** https://github.com/Shoebtamboli/rails_claude_skills/tree/main/lib/generators/claude/skills_library/rails-models
- **Website:** https://rubygems.org/gems/rails_claude_skills

## Install

```sh
agentstack add skill-shoebtamboli-rails-claude-skills-rails-models
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Rails Models (ActiveRecord)

## Quick Reference

| Pattern | Example |
|---------|---------|
| **Model Generation** | `rails g model User name:string email:string` |
| **Migration** | `rails g migration AddAgeToUsers age:integer` |
| **Validation** | `validates :email, presence: true, uniqueness: true` |
| **Association** | `has_many :posts, dependent: :destroy` |
| **Callback** | `before_save :normalize_email` |
| **Scope** | `scope :active, -> { where(active: true) }` |
| **Query** | `User.where(active: true).order(created_at: :desc)` |

## Model Definition

```ruby
class User  { where(active: true) }
  scope :recent, -> { order(created_at: :desc) }
  
  # Class methods
  def self.search(query)
    where("name ILIKE ?", "%#{query}%")
  end
  
  # Instance methods
  def full_name
    "#{first_name} #{last_name}"
  end
  
  private
  
  def normalize_email
    self.email = email.downcase.strip
  end
end
```

## Migrations

### Creating Tables

```ruby
class CreateUsers  { where(published: true) }, class_name: 'Book'
end

class Book  { where(published: true) }
  scope :recent, -> { order(created_at: :desc) }
  scope :by_author, ->(author_id) { where(author_id: author_id) }
  scope :created_between, ->(start_date, end_date) {
    where(created_at: start_date..end_date)
  }
  
  # Chaining scopes
  # Post.published.recent.limit(10)
end

# Query methods
Post.where(published: true)
Post.where("views > ?", 100)
Post.where(author_id: [1, 2, 3])
Post.where.not(category: 'draft')

# Ordering
Post.order(created_at: :desc)
Post.order(views: :desc, created_at: :asc)

# Limiting
Post.limit(10)
Post.offset(20).limit(10)

# Joins
Post.joins(:author)
Post.joins(:author, :comments)
Post.left_joins(:comments)

# Includes (eager loading)
Post.includes(:author, :comments)
Post.includes(author: :profile)

# Selecting specific fields
Post.select(:id, :title, :created_at)
Post.pluck(:title)
Post.pluck(:id, :title)

# Aggregations
Post.count
Post.average(:views)
Post.maximum(:views)
Post.minimum(:views)
Post.sum(:views)

# Group
Post.group(:category).count
Post.group(:author_id).average(:views)
```

## Enums

```ruby
class Post < ApplicationRecord
  enum status: {
    draft: 0,
    published: 1,
    archived: 2
  }
  
  # Or with prefix/suffix
  enum visibility: {
    public: 0,
    private: 1
  }, _prefix: :visibility
  
  # Usage:
  # post.draft!
  # post.published?
  # Post.published
  # post.visibility_public!
end
```

## Model Concerns

```ruby
# app/models/concerns/taggable.rb
module Taggable
  extend ActiveSupport::Concern
  
  included do
    has_many :taggings, as: :taggable
    has_many :tags, through: :taggings
  end
  
  class_methods do
    def tagged_with(tag_name)
      joins(:tags).where(tags: { name: tag_name })
    end
  end
  
  def tag_list
    tags.pluck(:name).join(', ')
  end
end

# Usage in model
class Post < ApplicationRecord
  include Taggable
end
```

## Best Practices

1. **Fat models, skinny controllers** - Business logic belongs in models
2. **Use scopes** for common queries
3. **Validate at database level** with constraints when possible
4. **Use indexes** for frequently queried columns
5. **Eager load associations** to avoid N+1 queries
6. **Use concerns** to share behavior across models
7. **Keep callbacks simple** - avoid complex logic
8. **Use transactions** for multi-step operations
9. **Avoid callbacks for cross-cutting concerns** - use service objects instead

## Common Pitfalls

- **N+1 queries**: Use `includes`, `preload`, or `eager_load`
- **Callback hell**: Keep callbacks simple, use service objects for complex logic
- **Mass assignment vulnerabilities**: Use strong parameters in controllers
- **Missing indexes**: Add indexes for foreign keys and frequently queried columns
- **Ignoring database constraints**: Add NOT NULL, unique constraints in migrations

## References

- [Rails Guides - Active Record](https://guides.rubyonrails.org/active_record_basics.html)
- [Rails Guides - Validations](https://guides.rubyonrails.org/active_record_validations.html)
- [Rails Guides - Associations](https://guides.rubyonrails.org/association_basics.html)
- [Rails Guides - Migrations](https://guides.rubyonrails.org/active_record_migrations.html)
- [Rails Guides - Queries](https://guides.rubyonrails.org/active_record_querying.html)

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Shoebtamboli](https://github.com/Shoebtamboli)
- **Source:** [Shoebtamboli/rails_claude_skills](https://github.com/Shoebtamboli/rails_claude_skills)
- **License:** MIT
- **Homepage:** https://rubygems.org/gems/rails_claude_skills

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-shoebtamboli-rails-claude-skills-rails-models
- Seller: https://agentstack.voostack.com/s/shoebtamboli
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.