Queries & Scopes in Ruby

From the Ruby on Rails cheat sheet · Models & Active Record · verified Jul 2026

Queries & Scopes

Query database with Active Record

ruby

# Find records
Post.find(1)
Post.find_by(title: 'Hello')
Post.where(published: true)
Post.all

# Chain queries
Post.where(published: true).order(created_at: :desc).limit(10)

✅ Use find_by instead of where().first

💡 includes() prevents N+1 query problems

🔍 Scopes make queries reusable and chainable

⚡ Use select() to fetch only needed columns

modelsqueriesactive-recordscopes

More Ruby tasks

Model Associations
Validations
Callbacks

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