rails--rails/activerecord/CHANGELOG.md

• Add configurable deprecation warning for singular associations

  This adds a deprecation warning when using the plural name of a singular associations in where. It is possible to opt into the new more performant behavior with config.active_record.allow_deprecated_singular_associations_name = false

  Adam Hess

• Run transactional callbacks on the freshest instance to save a given record within a transaction.

  When multiple Active Record instances change the same record within a transaction, Rails runs after_commit or after_rollback callbacks for only one of them. config.active_record.run_commit_callbacks_on_first_saved_instances_in_transaction was added to specify how Rails chooses which instance receives the callbacks. The framework defaults were changed to use the new logic.

  When config.active_record.run_commit_callbacks_on_first_saved_instances_in_transaction is true, transactional callbacks are run on the first instance to save, even though its instance state may be stale.

  When it is false, which is the new framework default starting with version 7.1, transactional callbacks are run on the instances with the freshest instance state. Those instances are chosen as follows:

  • In general, run transactional callbacks on the last instance to save a given record within the transaction.
  • There are two exceptions:
    • If the record is created within the transaction, then updated by another instance, after_create_commit callbacks will be run on the second instance. This is instead of the after_update_commit callbacks that would naively be run based on that instance’s state.
    • If the record is destroyed within the transaction, then after_destroy_commit callbacks will be fired on the last destroyed instance, even if a stale instance subsequently performed an update (which will have affected 0 rows).

  Cameron Bothner and Mitch Vollebregt

• Enable strict strings mode for SQLite3Adapter.

  Configures SQLite with a strict strings mode, which disables double-quoted string literals.

  SQLite has some quirks around double-quoted string literals. It first tries to consider double-quoted strings as identifier names, but if they don't exist it then considers them as string literals. Because of this, typos can silently go unnoticed. For example, it is possible to create an index for a non existing column. See SQLite documentation for more details.

  If you don't want this behavior, you can disable it via:

  # config/application.rb
  config.active_record.sqlite3_adapter_strict_strings_by_default = false
  

  Fixes #27782.

  fatkodima, Jean Boussier

• Resolve issue where a relation cache_version could be left stale.

  Previously, when reset was called on a relation object it did not reset the cache_versions ivar. This led to a confusing situation where despite having the correct data the relation still reported a stale cache_version.

  Usage:

  developers = Developer.all
  developers.cache_version
  
  Developer.update_all(updated_at: Time.now.utc + 1.second)
  
  developers.cache_version # Stale cache_version
  developers.reset
  developers.cache_version # Returns the current correct cache_version
  

  Fixes #45341.

  Austen Madden

• Add support for exclusion constraints (PostgreSQL-only).

  add_exclusion_constraint :invoices, "daterange(start_date, end_date) WITH &&", using: :gist, name: "invoices_date_overlap"
  remove_exclusion_constraint :invoices, name: "invoices_date_overlap"
  

  See PostgreSQL's CREATE TABLE ... EXCLUDE ... documentation for more on exclusion constraints.

  Alex Robbin

• change_column_null raises if a non-boolean argument is provided

  Previously if you provided a non-boolean argument, change_column_null would treat it as truthy and make your column nullable. This could be surprising, so now the input must be either true or false.

  change_column_null :table, :column, true # good
  change_column_null :table, :column, false # good
  change_column_null :table, :column, from: true, to: false # raises (previously this made the column nullable)
  

  Alex Ghiculescu

• Enforce limit on table names length.

  Fixes #45130.

  fatkodima

• Adjust the minimum MariaDB version for check constraints support.

  Eddie Lebow

• Fix Hstore deserialize regression.

  edsharp

• Add validity for PostgreSQL indexes.

  connection.index_exists?(:users, :email, valid: true)
  connection.indexes(:users).select(&:valid?)
  

  fatkodima

• Fix eager loading for models without primary keys.

  Anmol Chopra, Matt Lawrence, and Jonathan Hefner

• Avoid validating a unique field if it has not changed and is backed by a unique index.

  Previously, when saving a record, ActiveRecord will perform an extra query to check for the uniqueness of each attribute having a uniqueness validation, even if that attribute hasn't changed. If the database has the corresponding unique index, then this validation can never fail for persisted records, and we could safely skip it.

  fatkodima

• Stop setting sql_auto_is_null

  Since version 5.5 the default has been off, we no longer have to manually turn it off.

  Adam Hess

• Fix touch to raise an error for readonly columns.

  fatkodima

• Add ability to ignore tables by regexp for SQL schema dumps.

  ActiveRecord::SchemaDumper.ignore_tables = [/^_/]
  

  fatkodima

• Avoid queries when performing calculations on contradictory relations.

  Previously calculations would make a query even when passed a contradiction, such as User.where(id: []).count. We no longer perform a query in that scenario.

  This applies to the following calculations: count, sum, average, minimum and maximum

  Luan Vieira, John Hawthorn and Daniel Colson

• Allow using aliased attributes with insert_all/upsert_all.

  class Book < ApplicationRecord
    alias_attribute :title, :name
  end
  
  Book.insert_all [{ title: "Remote", author_id: 1 }], returning: :title
  

  fatkodima

• Support encrypted attributes on columns with default db values.

  This adds support for encrypted attributes defined on columns with default values. It will encrypt those values at creation time. Before, it would raise an error unless config.active_record.encryption.support_unencrypted_data was true.

  Jorge Manrubia and Dima Fatko

• Allow overriding reading_request? in DatabaseSelector::Resolver

  The default implementation checks if a request is a get? or head?, but you can now change it to anything you like. If the method returns true, Resolver#read gets called meaning the request could be served by the replica database.

  Alex Ghiculescu

• Remove ActiveRecord.legacy_connection_handling.

  Eileen M. Uchitelle

• rails db:schema:{dump,load} now checks ENV["SCHEMA_FORMAT"] before config

  Since rails db:structure:{dump,load} was deprecated there wasn't a simple way to dump a schema to both SQL and Ruby formats. You can now do this with an environment variable. For example:

  SCHEMA_FORMAT=sql rake db:schema:dump
  

  Alex Ghiculescu

• Fixed MariaDB default function support.

  Defaults would be written wrong in "db/schema.rb" and not work correctly if using db:schema:load. Further more the function name would be added as string content when saving new records.

  kaspernj

• Add active_record.destroy_association_async_batch_size configuration

  This allows applications to specify the maximum number of records that will be destroyed in a single background job by the dependent: :destroy_async association option. By default, the current behavior will remain the same: when a parent record is destroyed, all dependent records will be destroyed in a single background job. If the number of dependent records is greater than this configuration, the records will be destroyed in multiple background jobs.

  Nick Holden

• Fix remove_foreign_key with :if_exists option when foreign key actually exists.

  fatkodima

• Remove --no-comments flag in structure dumps for PostgreSQL

  This broke some apps that used custom schema comments. If you don't want comments in your structure dump, you can use:

  ActiveRecord::Tasks::DatabaseTasks.structure_dump_flags = ['--no-comments']
  

  Alex Ghiculescu

• Reduce the memory footprint of fixtures accessors.

  Until now fixtures accessors were eagerly defined using define_method. So the memory usage was directly dependent of the number of fixtures and test suites.

  Instead fixtures accessors are now implemented with method_missing, so they incur much less memory and CPU overhead.

  Jean Boussier

• Fix config.active_record.destroy_association_async_job configuration

  config.active_record.destroy_association_async_job should allow applications to specify the job that will be used to destroy associated records in the background for has_many associations with the dependent: :destroy_async option. Previously, that was ignored, which meant the default ActiveRecord::DestroyAssociationAsyncJob always destroyed records in the background.

  Nick Holden

• Fix change_column_comment to preserve column's AUTO_INCREMENT in the MySQL adapter

  fatkodima

• Fix quoting of ActiveSupport::Duration and Rational numbers in the MySQL adapter.

  Kevin McPhillips

• Allow column name with COLLATE (e.g., title COLLATE "C") as safe SQL string

  Shugo Maeda

• Permit underscores in the VERSION argument to database rake tasks.

  Eddie Lebow

• Reversed the order of INSERT statements in structure.sql dumps

  This should decrease the likelihood of merge conflicts. New migrations will now be added at the top of the list.

  For existing apps, there will be a large diff the next time structure.sql is generated.

  Alex Ghiculescu, Matt Larraz

• Fix PG.connect keyword arguments deprecation warning on ruby 2.7

  Fixes #44307.

  Nikita Vasilevsky

• Fix dropping DB connections after serialization failures and deadlocks.

  Prior to 6.1.4, serialization failures and deadlocks caused rollbacks to be issued for both real transactions and savepoints. This breaks MySQL which disallows rollbacks of savepoints following a deadlock.

  6.1.4 removed these rollbacks, for both transactions and savepoints, causing the DB connection to be left in an unknown state and thus discarded.

  These rollbacks are now restored, except for savepoints on MySQL.

  Thomas Morgan

• Make ActiveRecord::ConnectionPool Fiber-safe

  When ActiveSupport::IsolatedExecutionState.isolation_level is set to :fiber, the connection pool now supports multiple Fibers from the same Thread checking out connections from the pool.

  Alex Matchneer

• Add update_attribute! to ActiveRecord::Persistence

  Similar to update_attribute, but raises ActiveRecord::RecordNotSaved when a before_* callback throws :abort.

  class Topic < ActiveRecord::Base
    before_save :check_title
  
    def check_title
      throw(:abort) if title == "abort"
    end
  end
  
  topic = Topic.create(title: "Test Title")
  # #=> #<Topic title: "Test Title">
  topic.update_attribute!(:title, "Another Title")
  # #=> #<Topic title: "Another Title">
  topic.update_attribute!(:title, "abort")
  # raises ActiveRecord::RecordNotSaved
  

  Drew Tempelmeyer

• Avoid loading every record in ActiveRecord::Relation#pretty_print

  # Before
  pp Foo.all # Loads the whole table.
  
  # After
  pp Foo.all # Shows 10 items and an ellipsis.
  

  Ulysse Buonomo

• Change QueryMethods#in_order_of to drop records not listed in values.

  in_order_of now filters down to the values provided, to match the behavior of the Enumerable version.

  Kevin Newton

• Allow named expression indexes to be revertible.

  Previously, the following code would raise an error in a reversible migration executed while rolling back, due to the index name not being used in the index removal.

  add_index(:settings, "(data->'property')", using: :gin, name: :index_settings_data_property)
  

  Fixes #43331.

  Oliver Günther

• Fix incorrect argument in PostgreSQL structure dump tasks.

  Updating the --no-comment argument added in Rails 7 to the correct --no-comments argument.

  Alex Dent

• Fix migration compatibility to create SQLite references/belongs_to column as integer when migration version is 6.0.

  Reference/belongs_to in migrations with version 6.0 were creating columns as bigint instead of integer for the SQLite Adapter.

  Marcelo Lauxen

• Add a deprecation warning when prepared_statements configuration is not set for the mysql2 adapter.

  Thiago Araujo and Stefanni Brasil

• Fix QueryMethods#in_order_of to handle empty order list.

  Post.in_order_of(:id, []).to_a
  

  Also more explicitly set the column as secondary order, so that any other value is still ordered.

  Jean Boussier

• Fix quoting of column aliases generated by calculation methods.

  Since the alias is derived from the table name, we can't assume the result is a valid identifier.

  class Test < ActiveRecord::Base
    self.table_name = '1abc'
  end
  Test.group(:id).count
  # syntax error at or near "1" (ActiveRecord::StatementInvalid)
  # LINE 1: SELECT COUNT(*) AS count_all, "1abc"."id" AS 1abc_id FROM "1...
  

  Jean Boussier

• Add authenticate_by when using has_secure_password.

  authenticate_by is intended to replace code like the following, which returns early when a user with a matching email is not found:

  User.find_by(email: "...")&.authenticate("...")
  

  Such code is vulnerable to timing-based enumeration attacks, wherein an attacker can determine if a user account with a given email exists. After confirming that an account exists, the attacker can try passwords associated with that email address from other leaked databases, in case the user re-used a password across multiple sites (a common practice). Additionally, knowing an account email address allows the attacker to attempt a targeted phishing ("spear phishing") attack.

  authenticate_by addresses the vulnerability by taking the same amount of time regardless of whether a user with a matching email is found:

  User.authenticate_by(email: "...", password: "...")
  

  Jonathan Hefner

Please check 7-0-stable for previous changes.