Deep dive into ActiveRecord .scoping method in Rails

In Rails, multiple scopes can be created and chained together. What if we wish to apply a specific scope to a group of queries? Consider the following scenario: we have Post and Comment models and we want to perform few operations on public posts. # app/models/post.rb class Post < ActiveRecord::Base scope :public, -> { where(private: false) } endLoading development environment (Rails 7.0.0.alpha2) 3.0.0 :001 > Post.public.update_all(body: 'public post') Post Update All (4.1ms) UPDATE "posts" SET "body" = ? WHERE "posts"."private" = ? [["body", "public post"], ["private", 0]] 3.0.0

Rails 7 introduces partial_inserts config for ActiveRecord

Rails 7 adds the partial_inserts config to config.active_record that is used to control partial writes when creating a new record. config.active_record.partial_inserts is a boolean value and controls whether or not partial writes are used when creating new records (i.e. whether inserts only set attributes that are different from the default). Configuring config.active_record.partial_inserts In a newly created Rails 7.0 application, config.load_defaults 7.0 is set by default in application.rb. The default value of partial_inserts for config.load_defaults 7.0 is false and for

Rails 7 supports tracking of belongs_to association

One of the most convenient features of Rails is the ability to track attribute changes. Rails 7 is releasing soon and bringing in a lot of new features as a treat for developers. One of the many features that Rails 7 is introducing, is that we can also track the associated object. This Rails ActiveRecord specific PR has added two methods for tracking the changes for the belongs_to association. In this article, we will discuss these two new methods with the help of examples. 1. association_changed?The association_changed? method tells if a different associated object has been

Side effects of Active Record's new feature #invert_where in Rails 7

Rails 7 is introducing a new method invert_where that will invert all scope conditions. It allows us to invert an entire where clause instead of manually applying conditions. We can either chain invert_where to a scope or to a where condition. class Account scope :active, -> { where(active: true) } end Account.active.invert_where => "SELECT \"accounts\".* FROM \"accounts\" WHERE \"accounts\".\"active\" != 1"Account.where(active: true).invert_where => "SELECT \"accounts\".* FROM \"accounts\" WHERE \"accounts\".\"active\" != 1"What are the various side effects of using invert_where?1. The invert_where method inverts all the where

Active Record Encryption in Rails 7

If you're hosting your web server in a particular region, it might be necessary to comply with the GDPR norms of that region. Anonymizing and encrypting data becomes necessary in such situations. In this blog, we will discuss the attribute encryption that Rails 7 provides right out of the box. And we will also see the Deterministic & Non Deterministic approaches. (If you're using Rails version lesser than 7, check out our previous blog here on how to write a custom encryption framework.) ActiveRecord attribute encryption in Ruby on Rails for better securityIn this blog post, we will explore a

Speeding up Rails 7's Controller Actions using ActiveRecord's #load_async

Most of the time in a web application, a single API request consists of multiple database queries. For example: class DashboardsController < ApplicationController def dashboard @users = User.some_complex_scope.load_async @products = Product.some_complex_scope.load_async @library_files = LibraryFile.some_complex_scope.load_async end end Quoting snippet from load_async PR description from rails repository. The queries are executed synchronously, which mostly isn’t a huge concern. But, as the database grows larger in size, the response time of requests is getting longer. A significant part of the query time is often just I/O waits.

Speed up time-sensitive database process in Rails applications using a Connection pool, Threads, and Arel

Sometimes dealing with DB processes in a Rails application consume a lot of time. Often there are a bunch of small and simple DB queries that go endless. For example, bulk insertions or bulk updates in tables. Dividing it into various background jobs is an idle solution. In a few scenarios, we can't prefer background jobs e.g. the change you apply, makes the existing data invalid. In this article, we will see how to complete a large set of DB queries under minutes which would otherwise take hours if not optimized. It's a better practice to create a rake

Optimistic vs. Pessimistic locking in Rails

While performing concurrent operations, a database must ensure data integrity. ACID compliant relational database ensures this data integrity through its locking mechanism. ACID = Atomicity, Consistency, Isolation, Durability Locks can be at the database, table, page, or row level. Here is a beginner's guide to database locking in PostgreSQL. In this article, let's see how Rails provides a mechanism for optimistic locking on ActiveRecord models. However, before we proceed, let us first understand the basics of optimistic and pessimistic locking. What is optimistic locking? Let's take an example of two admin users, Mohan and Ritesh, managing the product inventory in their

Automatic counter-cache issue with has-many association in Rails 4.2.x

Recently while working on one of our project there was an requirement of tracking count of records associated with has-many association. But also there was "is_hidden" flag set on some of the records which I do not suppose to count in counter as those were hidden records. So default counter_cache option of rails active-record was not appropriate in this case which automatically counts and caches the number of associated records and keeps cache updated. Refer following model code for this. class Order < ActiveRecord::Base belongs_to :customer, counter_cache: true end class Customer < ActiveRecord:

ActiveRecord::Dirty

Performing an action via a callback is fairly easy and doable. Sometimes requirement may be a bit enhance that we need to track every change now and then. On the same note, if we have associations and we wanted to make some changes that needs to be reflected on previous and new values, this dirty concepts can save our time. This module gives a way to track changes done in an active-record object. By default, rails include ActiveRecord::Dirty this module. This gives many powerful methods that helps us to track attribute changes. This methods are based on the attribute