• Gracefully handle Timeout.timeout firing during connection configuration.

  Use of Timeout.timeout could result in improperly initialized database connection.

  This could lead to a partially configured connection being used, resulting in various exceptions, the most common being with the PostgreSQLAdapter raising undefined methodkey?' for nil orTypeError: wrong argument type nil (expected PG::TypeMap)`.

  Jean Boussier

Rails 8.0.2 (March 12, 2025)

• Fix inverting rename_enum_value when :from/:to are provided.

  fatkodima

• Prevent persisting invalid record.

  Edouard Chin

• Fix inverting drop_table without options.

  fatkodima

• Fix count with group by qualified name on loaded relation.

  Ryuta Kamizono

• Fix sum with qualified name on loaded relation.

  Chris Gunther

• The SQLite3 adapter quotes non-finite Numeric values like "Infinity" and "NaN".

  Mike Dalessio

• Handle libpq returning a database version of 0 on no/bad connection in PostgreSQLAdapter.

  Before, this version would be cached and an error would be raised during connection configuration when comparing it with the minimum required version for the adapter. This meant that the connection could never be successfully configured on subsequent reconnection attempts.

  Now, this is treated as a connection failure consistent with libpq, raising a ::ActiveRecord::ConnectionFailed and ensuring the version isn't cached, which allows the version to be retrieved on the next connection attempt.

  Joshua Young, Rian McGuire

• Fix error handling during connection configuration.

  Active Record wasn't properly handling errors during the connection configuration phase. This could lead to a partially configured connection being used, resulting in various exceptions, the most common being with the PostgreSQLAdapter raising undefined methodkey?' for nil orTypeError: wrong argument type nil (expected PG::TypeMap)`.

  Jean Boussier

• Fix a case where a non-retryable query could be marked retryable.

  Hartley McGuire

• Handle circular references when autosaving associations.

  zzak

• PoolConfig no longer keeps a reference to the connection class.

  Keeping a reference to the class caused subtle issues when combined with reloading in development. Fixes #54343.

  Mike Dalessio

• Fix SQL notifications sometimes not sent when using async queries.

  Post.async_count
  ActiveSupport::Notifications.subscribed(->(*) { "Will never reach here" }) do
    Post.count
  end

  In rare circumstances and under the right race condition, Active Support notifications would no longer be dispatched after using an asynchronous query. This is now fixed.

  Edouard Chin

• Fix support for PostgreSQL enum types with commas in their name.

  Arthur Hess

• Fix inserts on MySQL with no RETURNING support for a table with multiple auto populated columns.

  Nikita Vasilevsky

• Fix joining on a scoped association with string joins and bind parameters.

  class Instructor < ActiveRecord::Base
    has_many :instructor_roles, -> { active }
  end
  
  class InstructorRole < ActiveRecord::Base
    scope :active, -> {
      joins("JOIN students ON instructor_roles.student_id = students.id")
      .where(students { status: 1 })
    }
  end
  
  Instructor.joins(:instructor_roles).first

  The above example would result in ::ActiveRecord::StatementInvalid because the active scope bind parameters would be lost.

  Jean Boussier

• Fix a potential race condition with system tests and transactional fixtures.

  Sjoerd Lagarde

• Fix autosave associations to no longer validated unmodified associated records.

  Active Record was incorrectly performing validation on associated record that weren't created nor modified as part of the transaction:

  Post.create!(author: User.find(1)) # Fail if user is invalid

  Jean Boussier

• Remember when a database connection has recently been verified (for two seconds, by default), to avoid repeated reverifications during a single request.

  This should recreate a similar rate of verification as in Rails 7.1, where connections are leased for the duration of a request, and thus only verified once.

  Matthew Draper

Rails 8.0.1 (December 13, 2024)

• Fix removing foreign keys with :restrict action for MySQL.

  fatkodima

• Fix a race condition in ActiveRecord::Base#method_missing when lazily defining attributes.

  If multiple thread were concurrently triggering attribute definition on the same model, it could result in a NoMethodError being raised.

  Jean Boussier

• Fix MySQL default functions getting dropped when changing a column's nullability.

  Bastian Bartmann

• Fix add_unique_constraint/add_check_constraint/add_foreign_key to be revertible when given invalid options.

  fatkodima

• Fix asynchronous destroying of polymorphic belongs_to associations.

  fatkodima

• Fix insert_all to not update existing records.

  fatkodima

• NOT VALID constraints should not dump in create_table.

  Ryuta Kamizono

• Fix finding by nil composite primary key association.

  fatkodima

• Properly reset composite primary key configuration when setting a primary key.

  fatkodima

• Fix Mysql2Adapter support for prepared statements

  Using prepared statements with MySQL could result in a NoMethodError exception.

  Jean Boussier, Leo Arnold, zzak

• Fix parsing of SQLite foreign key names when they contain non-ASCII characters

  Zacharias Knudsen

• Fix parsing of MySQL 8.0.16+ CHECK constraints when they contain new lines.

  Steve Hill

• Ensure normalized attribute queries use IS NULL consistently for nil and normalized nil values.

  Joshua Young

• Fix sum when performing a grouped calculation.

  User.group(:friendly).sum no longer worked. This is fixed.

  Edouard Chin

• Restore back the ability to pass only database name to DATABASE_URL.

  fatkodima

Rails 8.0.0.1 (December 10, 2024)

• No changes.

Rails 8.0.0 (November 07, 2024)

• Fix support for query_cache: false in database.yml.

  query_cache: false would no longer entirely disable the Active Record query cache.

  zzak

Rails 8.0.0.rc2 (October 30, 2024)

• NULLS NOT DISTINCT works with UNIQUE CONSTRAINT as well as UNIQUE INDEX.

  Ryuta Kamizono

• The db:prepare task no longer loads seeds when a non-primary database is created.

  Previously, the db:prepare task would load seeds whenever a new database is created, leading to potential loss of data if a database is added to an existing environment.

  Introduces a new database config property seeds to control whether seeds are loaded during db:prepare which defaults to true for primary database configs and false otherwise.

  Fixes #53348.

  Mike Dalessio

• PG::UnableToSend: no connection to the server is now retryable as a connection-related exception

  Kazuma Watanabe

• Fix strict loading propagation even if statement cache is not used.

  Ryuta Kamizono

• Allow rename_enum accepts two from/to name arguments as rename_table does so.

  Ryuta Kamizono

Rails 8.0.0.rc1 (October 19, 2024)

• Remove deprecated support to setting ENV["SCHEMA_CACHE"].

  Rafael Mendonça França

• Remove deprecated support to passing a database name to cache_dump_filename.

  Rafael Mendonça França

• Remove deprecated ActiveRecord::ConnectionAdapters::ConnectionPool#connection.

  Rafael Mendonça França

• Remove deprecated config.active_record.sqlite3_deprecated_warning.

  Rafael Mendonça França

• Remove deprecated config.active_record.warn_on_records_fetched_greater_than.

  Rafael Mendonça França

• Remove deprecated support for defining enum with keyword arguments.

  Rafael Mendonça França

• Remove deprecated support to finding database adapters that aren't registered to Active Record.

  Rafael Mendonça França

• Remove deprecated config.active_record.allow_deprecated_singular_associations_name.

  Rafael Mendonça França

• Remove deprecated config.active_record.commit_transaction_on_non_local_return.

  Rafael Mendonça França

• Fix incorrect SQL query when passing an empty hash to ActiveRecord::Base.insert.

  David Stosik

• Allow to save records with polymorphic join tables that have inverse_of specified.

  Markus Doits

• Fix association scopes applying on the incorrect join when using a polymorphic has_many through:.

  Joshua Young

• Allow ActiveRecord::Base#pluck to accept hash arguments with symbol and string values.

  Post.joins(:comments).pluck(:id, comments: :id)
  Post.joins(:comments).pluck("id", "comments" => "id")

  Joshua Young

• Make Float distinguish between float4 and float8 in PostgreSQL.

  Fixes #52742

  Ryota Kitazawa, Takayuki Nagatomi

Rails 8.0.0.beta1 (September 26, 2024)

• Allow drop_table to accept an array of table names.

  This will let you to drop multiple tables in a single call.

  ActiveRecord::Base.lease_connection.drop_table(:users, :posts)

  Gabriel Sobrinho

• Add support for PostgreSQL IF NOT EXISTS via the :if_not_exists option on the add_enum_value method.

  Ariel Rzezak

• When running db:migrate on a fresh database, load the databases schemas before running migrations.

  Andrew Novoselac, Marek Kasztelnik

• Fix an issue where .left_outer_joins used with multiple associations that have the same child association but different parents does not join all parents.

  Previously, using .left_outer_joins with the same child association would only join one of the parents.

  Now it will correctly join both parents.

  Fixes #41498.

  Garrett Blehm

• Deprecate unsigned_float and unsigned_decimal short-hand column methods.

  As of MySQL 8.0.17, the UNSIGNED attribute is deprecated for columns of type FLOAT, DOUBLE, and DECIMAL. Consider using a simple CHECK constraint instead for such columns.

  https://dev.mysql.com/doc/refman/8.0/en/numeric-type-syntax.html

  Ryuta Kamizono

• Drop MySQL 5.5 support.

  MySQL 5.5 is the only version that does not support datetime with precision, which we have supported in the core. Now we support MySQL 5.6.4 or later, which is the first version to support datetime with precision.

  Ryuta Kamizono

• Make Active Record asynchronous queries compatible with transactional fixtures.

  Previously transactional fixtures would disable asynchronous queries, because transactional fixtures impose all queries use the same connection.

  Now asynchronous queries will use the connection pinned by transactional fixtures, and behave much closer to production.

  Jean Boussier

• Deserialize binary data before decrypting

  This ensures that we call PG::Connection.unescape_bytea on PostgreSQL before decryption.

  Donal McBreen

• Ensure ActiveRecord::Encryption.config is always ready before access.

  Previously, ::ActiveRecord::Encryption configuration was deferred until ::ActiveRecord::Base was loaded. Therefore, accessing ActiveRecord::Encryption.config properties before ::ActiveRecord::Base was loaded would give incorrect results.

  ::ActiveRecord::Encryption now has its own loading hook so that its configuration is set as soon as needed.

  When ::ActiveRecord::Base is loaded, even lazily, it in turn triggers the loading of ::ActiveRecord::Encryption, thus preserving the original behavior of having its config ready before any use of ::ActiveRecord::Base.

  Maxime Réty

• Add TimeZoneConverter#== method, so objects will be properly compared by their type, scale, limit & precision.

  Address #52699.

  Ruy Rocha

• Add support for SQLite3 full-text-search and other virtual tables.

  Previously, adding sqlite3 virtual tables messed up schema.rb.

  Now, virtual tables can safely be added using create_virtual_table.

  Zacharias Knudsen

• Support use of alternative database interfaces via the database_cli ActiveRecord configuration option.

  Rails.application.configure do
    config.active_record.database_cli = { postgresql: "pgcli" }
  end

  T S Vallender

• Add support for dumping table inheritance and native partitioning table definitions for PostgeSQL adapter

  Justin Talbott

• Add support for ::ActiveRecord::Point type casts using Hash values

  This allows ::ActiveRecord::Point to be cast or serialized from a hash with :x and :y keys of numeric values, mirroring the functionality of existing casts for string and array values. Both string and symbol keys are supported.

  class PostgresqlPoint < ActiveRecord::Base
    attribute :x, :point
    attribute :y, :point
    attribute :z, :point
  end
  
  val = PostgresqlPoint.new({
    x: '(12.34, -43.21)',
    y: [12.34, '-43.21'],
    z: {x: '12.34', y: -43.21}
  })
  ActiveRecord::Point.new(12.32, -43.21) == val.x == val.y == val.z

  Stephen Drew

• Replace SQLite3::Database#busy_timeout with #busy_handler_timeout=.

  Provides a non-GVL-blocking, fair retry interval busy handler implementation.

  Stephen Margheim

• SQLite3Adapter: Translate SQLite3::BusyException into ::ActiveRecord::StatementTimeout.

  Matthew Nguyen

• Include schema name in enable_extension statements in db/schema.rb.

  The schema dumper will now include the schema name in generated enable_extension statements if they differ from the current schema.

  For example, if you have a migration:

  enable_extension "heroku_ext.pgcrypto"
  enable_extension "pg_stat_statements"

  then the generated schema dump will also contain:

  enable_extension "heroku_ext.pgcrypto"
  enable_extension "pg_stat_statements"

  Tony Novak

• Fix ActiveRecord::Encryption::EncryptedAttributeType#type to return actual cast type.

  Vasiliy Ermolovich

• SQLite3Adapter: Bulk insert fixtures.

  Previously one insert command was executed for each fixture, now they are aggregated in a single bulk insert command.

  Lázaro Nixon

• PostgreSQLAdapter: Allow disable_extension to be called with schema-qualified name.

  For parity with enable_extension, the disable_extension method can be called with a schema-qualified name (e.g. disable_extension "myschema.pgcrypto"). Note that PostgreSQL's DROP EXTENSION does not actually take a schema name (unlike CREATE EXTENSION), so the resulting SQL statement will only name the extension, e.g. DROP EXTENSION IF EXISTS "pgcrypto".

  Tony Novak

• Make create_schema / drop_schema reversible in migrations.

  Previously, create_schema and drop_schema were irreversible migration operations.

  Tony Novak

• Support batching using custom columns.

  Product.in_batches(cursor: [:shop_id, :id]) do |relation|
    # do something with relation
  end

  fatkodima

• Use SQLite IMMEDIATE transactions when possible.

  Transactions run against the SQLite3 adapter default to IMMEDIATE mode to improve concurrency support and avoid busy exceptions.

  Stephen Margheim

• Raise specific exception when a connection is not defined.

  The new ConnectionNotDefined exception provides connection name, shard and role accessors indicating the details of the connection that was requested.

  Hana Harencarova, Matthew Draper

• Delete the deprecated constant ActiveRecord::ImmutableRelation.

  Xavier Noria

• Fix duplicate callback execution when child autosaves parent with has_one and belongs_to.

  Before, persisting a new child record with a new associated parent record would run before_validation, after_validation, before_save and after_save callbacks twice.

  Now, these callbacks are only executed once as expected.

  Joshua Young

• ::ActiveRecord::Encryption::Encryptor now supports a :compressor option to customize the compression algorithm used.

  module ZstdCompressor
    def self.deflate(data)
      Zstd.compress(data)
    end
  
    def self.inflate(data)
      Zstd.decompress(data)
    end
  end
  
  class User
    encrypts :name, compressor: ZstdCompressor
  end

  You disable compression by passing compress: false.

  class User
    encrypts :name, compress: false
  end

  heka1024

• Add condensed #inspect for ConnectionPool, AbstractAdapter, and DatabaseConfig.

  Hartley McGuire

• Add .shard_keys, .sharded?, & .connected_to_all_shards methods.

  class ShardedBase < ActiveRecord::Base
      self.abstract_class = true
  
      connects_to shards: {
        shard_one: { writing: :shard_one },
        shard_two: { writing: :shard_two }
      }
  end
  
  class ShardedModel < ShardedBase
  end
  
  ShardedModel.shard_keys => [:shard_one, :shard_two]
  ShardedModel.sharded? => true
  ShardedBase.connected_to_all_shards { ShardedModel.current_shard } => [:shard_one, :shard_two]

  Nony Dutton

• Add a filter option to in_order_of to prioritize certain values in the sorting without filtering the results by these values.

  Igor Depolli

• Fix an issue where the IDs reader method did not return expected results for preloaded associations in models using composite primary keys.

  Jay Ang

• Allow to configure strict_loading_mode globally or within a model.

  Defaults to :all, can be changed to :n_plus_one_only.

  Garen Torikian

• Add ActiveRecord::Relation#readonly?.

  Reflects if the relation has been marked as readonly.

  Theodor Tonum

• Improve ::ActiveRecord::Store to raise a descriptive exception if the column is not either structured (e.g., PostgreSQL hstore+/+json, or MySQL json) or declared serializable via ActiveRecord.store.

  Previously, a NoMethodError would be raised when the accessor was read or written:

  NoMethodError: undefined method `accessor' for an instance of ActiveRecord::Type::Text

  Now, a descriptive ConfigurationError is raised:

  ActiveRecord::ConfigurationError: the column 'metadata' has not been configured as a store.
    Please make sure the column is declared serializable via 'ActiveRecord.store' or, if your
    database supports it, use a structured column type like hstore or json.

  Mike Dalessio

• Fix inference of association model on nested models with the same demodularized name.

  E.g. with the following setup:

  class Nested::Post < ApplicationRecord
    has_one :post, through: :other
  end

  Before, #post would infer the model as Nested::Post, but now it correctly infers Post.

  Joshua Young

• Add public method for checking if a table is ignored by the schema cache.

  Previously, an application would need to reimplement ignored_table? from the schema cache class to check if a table was set to be ignored. This adds a public method to support this and updates the schema cache to use that directly.

  ActiveRecord.schema_cache_ignored_tables = ["developers"]
  ActiveRecord.schema_cache_ignored_table?("developers")
  #=> true

  Eileen M. Uchitelle

Please check [7-2-stable]) for previous changes.