Created
September 12, 2023 13:58
-
-
Save kddnewton/4aa44109089c7c6346b345a04667a521 to your computer and use it in GitHub Desktop.
Cached lookup
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# frozen_string_literal: true | |
require "bundler/inline" | |
gemfile(true) do | |
source "https://rubygems.org" | |
gem "activerecord", "~> 7.0.0" | |
gem "sqlite3" | |
end | |
require "active_record" | |
require "minitest/autorun" | |
require "logger" | |
ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:") | |
ActiveRecord::Base.logger = Logger.new(STDOUT) | |
ActiveRecord::Schema.define do | |
create_table :organizations, force: true do |t| | |
end | |
create_table :users, force: true do |t| | |
t.string :name | |
end | |
create_table :memberships, force: true do |t| | |
t.references :organization | |
t.references :user | |
end | |
end | |
class Organization < ActiveRecord::Base | |
has_many :memberships | |
has_many :users, through: :memberships | |
def member?(user) | |
user.has_attribute?(:cached_member) && user.cached_member | |
end | |
end | |
class User < ActiveRecord::Base | |
has_many :memberships | |
end | |
class Membership < ActiveRecord::Base | |
belongs_to :organization | |
belongs_to :user | |
end | |
org1, org2 = *2.times.map { Organization.create! } | |
org1.users.create!([{ name: "Org1Foo" }, { name: "Org2Bar" }]) | |
org2.users.create!([{ name: "Org1Foo" }, { name: "Org2Bar" }, { name: "Org2Baz"}]) | |
# Reload to ensure nothing is cached. | |
org1.reload | |
org2.reload | |
# Get a list of the queries that are executed to ensure we're not hitting the | |
# database more than we need to. | |
queries = [] | |
ActiveSupport::Notifications.subscribe("sql.active_record") do |*, payload| | |
queries << payload[:sql] | |
end | |
# Iterate through and call member? for each user. | |
org1.users.select("users.*, TRUE as cached_member").each { |user| puts org1.member?(user) } | |
org2.users.each { |user| puts org1.member?(user) } | |
# Check that only the two user queries were executed. | |
p queries |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment