Find Records

This guide shows you how to find records by their primary key or attributes.

Find by ID

user = User.find(1)
if user
  puts "Found: #{user.name}"
else
  puts "Not found"
end

Find by ID (raise if not found)

user = User.find!(1)  # Raises if not found
puts user.name

Find by Attribute

user = User.find_by(email: "[e-mail]")
puts user.try(&.name)

Find by Multiple Attributes

post = Post.find_by(user_id: 1, published: true)

Find First Record

user = User.first
puts user.try(&.name)

Find Last Record

user = User.last
puts user.try(&.name)

Find All Records

users = User.all
users.each { |u| puts u.name }

Find with Order

# First by creation date
oldest = User.order(created_at: :asc).first

# Last by creation date
newest = User.order(created_at: :desc).first

Check if Record Exists

exists = User.exists?(email: "[e-mail]")
puts "User exists: #{exists}"

Find or Initialize

user = User.find_by(email: "[e-mail]")
user ||= User.new("John", "[e-mail]")

Safe Navigation

Use try for safe access:

user = User.find(1)
name = user.try(&.name) || "Unknown"

Verify Find Works

User.create!(name: "John", email: "[e-mail]")

User.find_by(name: "John")  # => User instance
User.find_by(name: "Jane")  # => nil

Related

• Filter with Where Clauses

• Build Complex Queries

• Paginate Results