CHANGELOG.md

• Fix dependent: :destroy issue for has_one/belongs_to relationship where the parent class was getting deleted when the child was not.

  Fixes #32022.

  Fernando Gorodscy

• Whitelist NULLS FIRST and NULLS LAST in order clauses too.

  Xavier Noria

• Fix that after commit callbacks on update does not triggered when optimistic locking is enabled.

  Ryuta Kamizono

• Fix #columns_for_distinct of MySQL and PostgreSQL to make ActiveRecord::FinderMethods#limited_ids_for use correct primary key values even if ORDER BY columns include other table's primary key.

  Fixes #28364.

  Takumi Kagiyama

• Make reflection.klass raise if polymorphic? not to be misused.

  Fixes #31876.

  Ryuta Kamizono

Rails 5.2.0.rc1 (January 30, 2018)

• PostgreSQL: Allow pg-1.0 gem to be used with Active Record.

  Lars Kanis

• Deprecate expand_hash_conditions_for_aggregates without replacement. Using a Relation for performing queries is the prefered API.

  Ryuta Kamizono

• Fix not expanded problem when passing an Array object as argument to the where method using composed_of column.

  david_balance = customers(:david).balance
  Customer.where(balance: [david_balance]).to_sql
  
  # Before: WHERE `customers`.`balance` = NULL
  # After : WHERE `customers`.`balance` = 50
  

  Fixes #31723.

  Yutaro Kanagawa

• Fix count(:all) with eager loading and having an order other than the driving table.

  Fixes #31783.

  Ryuta Kamizono

• Clear the transaction state when an Active Record object is duped.

  Fixes #31670.

  Yuriy Ustushenko

• Support for PostgreSQL foreign tables.

  fatkodima

• Fix relation merger issue with left_outer_joins.

  Mehmet Emin İNAÇ

• Don't allow destroyed object mutation after save or save! is called.

  Ryuta Kamizono

• Take into account association conditions when deleting through records.

  Fixes #18424.

  Piotr Jakubowski

• Fix nested has_many :through associations on unpersisted parent instances.

  For example, if you have

  class Post < ActiveRecord::Base
    belongs_to :author
    has_many :books, through: :author
    has_many :subscriptions, through: :books
  end
  
  class Author < ActiveRecord::Base
    has_one :post
    has_many :books
    has_many :subscriptions, through: :books
  end
  
  class Book < ActiveRecord::Base
    belongs_to :author
    has_many :subscriptions
  end
  
  class Subscription < ActiveRecord::Base
    belongs_to :book
  end
  

  Before:

  If post is not persisted, then post.subscriptions will be empty.

  After:

  If post is not persisted, then post.subscriptions can be set and used just like it would if post were persisted.

  Fixes #16313.

  Zoltan Kiss

• Fixed inconsistency with first(n) when used with limit(). The first(n) finder now respects the limit(), making it consistent with relation.to_a.first(n), and also with the behavior of last(n).

  Fixes #23979.

  Brian Christian

• Use count(:all) in HasManyAssociation#count_records to prevent invalid SQL queries for association counting.

  Klas Eskilson

• Fix to invoke callbacks when using update_attribute.

  Mike Busch

• Fix count(:all) to correctly work distinct with custom SELECT list.

  Ryuta Kamizono

• Using subselect for delete_all with limit or offset.

  Ryuta Kamizono

• Undefine attribute methods on descendants when resetting column information.

  Chris Salzberg

• Log database query callers

  Add verbose_query_logs configuration option to display the caller of database queries in the log to facilitate N+1 query resolution and other debugging.

  Enabled in development only for new and upgraded applications. Not recommended for use in the production environment since it relies on Ruby's Kernel#caller_locations which is fairly slow.

  Olivier Lacan

• Fix conflicts counter_cache with touch: true by optimistic locking.

  # create_table :posts do |t|
  #   t.integer :comments_count, default: 0
  #   t.integer :lock_version
  #   t.timestamps
  # end
  class Post < ApplicationRecord
  end
  
  # create_table :comments do |t|
  #   t.belongs_to :post
  # end
  class Comment < ApplicationRecord
    belongs_to :post, touch: true, counter_cache: true
  end
  

  Before:

  post = Post.create!
  # => begin transaction
       INSERT INTO "posts" ("created_at", "updated_at", "lock_version")
       VALUES ("2017-12-11 21:27:11.387397", "2017-12-11 21:27:11.387397", 0)
       commit transaction
  
  comment = Comment.create!(post: post)
  # => begin transaction
       INSERT INTO "comments" ("post_id") VALUES (1)
  
       UPDATE "posts" SET "comments_count" = COALESCE("comments_count", 0) + 1,
       "lock_version" = COALESCE("lock_version", 0) + 1 WHERE "posts"."id" = 1
  
       UPDATE "posts" SET "updated_at" = '2017-12-11 21:27:11.398330',
       "lock_version" = 1 WHERE "posts"."id" = 1 AND "posts"."lock_version" = 0
       rollback transaction
  # => ActiveRecord::StaleObjectError: Attempted to touch a stale object: Post.
  
  Comment.take.destroy!
  # => begin transaction
       DELETE FROM "comments" WHERE "comments"."id" = 1
  
       UPDATE "posts" SET "comments_count" = COALESCE("comments_count", 0) - 1,
       "lock_version" = COALESCE("lock_version", 0) + 1 WHERE "posts"."id" = 1
  
       UPDATE "posts" SET "updated_at" = '2017-12-11 21:42:47.785901',
       "lock_version" = 1 WHERE "posts"."id" = 1 AND "posts"."lock_version" = 0
       rollback transaction
  # => ActiveRecord::StaleObjectError: Attempted to touch a stale object: Post.
  

  After:

  post = Post.create!
  # => begin transaction
       INSERT INTO "posts" ("created_at", "updated_at", "lock_version")
       VALUES ("2017-12-11 21:27:11.387397", "2017-12-11 21:27:11.387397", 0)
       commit transaction
  
  comment = Comment.create!(post: post)
  # => begin transaction
       INSERT INTO "comments" ("post_id") VALUES (1)
  
       UPDATE "posts" SET "comments_count" = COALESCE("comments_count", 0) + 1,
       "lock_version" = COALESCE("lock_version", 0) + 1,
       "updated_at" = '2017-12-11 21:37:09.802642' WHERE "posts"."id" = 1
       commit transaction
  
  comment.destroy!
  # => begin transaction
       DELETE FROM "comments" WHERE "comments"."id" = 1
  
       UPDATE "posts" SET "comments_count" = COALESCE("comments_count", 0) - 1,
       "lock_version" = COALESCE("lock_version", 0) + 1,
       "updated_at" = '2017-12-11 21:39:02.685520' WHERE "posts"."id" = 1
       commit transaction
  

  Fixes #31199.

  bogdanvlviv

• Add support for PostgreSQL operator classes to add_index.

  Example:

  add_index :users, :name, using: :gist, opclass: { name: :gist_trgm_ops }
  

  Greg Navis

• Don't allow scopes to be defined which conflict with instance methods on Relation.

  Fixes #31120.

  kinnrot

Rails 5.2.0.beta2 (November 28, 2017)

• No changes.

Rails 5.2.0.beta1 (November 27, 2017)

• Add new error class QueryCanceled which will be raised when canceling statement due to user request.

  Ryuta Kamizono

• Add #up_only to database migrations for code that is only relevant when migrating up, e.g. populating a new column.

  Rich Daley

• Require raw SQL fragments to be explicitly marked when used in relation query methods.

  Before:

  Article.order("LENGTH(title)")
  

  After:

  Article.order(Arel.sql("LENGTH(title)"))
  

  This prevents SQL injection if applications use the [strongly discouraged] form Article.order(params[:my_order]), under the mistaken belief that only column names will be accepted.

  Raw SQL strings will now cause a deprecation warning, which will become an UnknownAttributeReference error in Rails 6.0. Applications can opt in to the future behavior by setting allow_unsafe_raw_sql to :disabled.

  Common and judged-safe string values (such as simple column references) are unaffected:

  Article.order("title DESC")
  

  Ben Toews

• update_all will now pass its values to Type#cast before passing them to Type#serialize. This means that update_all(foo: 'true') will properly persist a boolean.

  Sean Griffin

• Add new error class StatementTimeout which will be raised when statement timeout exceeded.

  Ryuta Kamizono

• Fix bin/rails db:migrate with specified VERSION. bin/rails db:migrate with empty VERSION behaves as without VERSION. Check a format of VERSION: Allow a migration version number or name of a migration file. Raise error if format of VERSION is invalid. Raise error if target migration doesn't exist.

  bogdanvlviv

• Fixed a bug where column orders for an index weren't written to db/schema.rb when using the sqlite adapter.

  Fixes #30902.

  Paul Kuruvilla

• Remove deprecated method #sanitize_conditions.

  Rafael Mendonça França

• Remove deprecated method #scope_chain.

  Rafael Mendonça França

• Remove deprecated configuration .error_on_ignored_order_or_limit.

  Rafael Mendonça França

• Remove deprecated arguments from #verify!.

  Rafael Mendonça França

• Remove deprecated argument name from #indexes.

  Rafael Mendonça França

• Remove deprecated method ActiveRecord::Migrator.schema_migrations_table_name.

  Rafael Mendonça França

• Remove deprecated method supports_primary_key?.

  Rafael Mendonça França

• Remove deprecated method supports_migrations?.

  Rafael Mendonça França

• Remove deprecated methods initialize_schema_migrations_table and initialize_internal_metadata_table.

  Rafael Mendonça França

• Raises when calling lock! in a dirty record.

  Rafael Mendonça França

• Remove deprecated support to passing a class to :class_name on associations.

  Rafael Mendonça França

• Remove deprecated argument default from index_name_exists?.

  Rafael Mendonça França

• Remove deprecated support to quoted_id when typecasting an Active Record object.

  Rafael Mendonça França

• Fix bin/rails db:setup and bin/rails db:test:prepare create wrong ar_internal_metadata's data for a test database.

  Before:

  $ RAILS_ENV=test rails dbconsole
  > SELECT * FROM ar_internal_metadata;
  key|value|created_at|updated_at
  environment|development|2017-09-11 23:14:10.815679|2017-09-11 23:14:10.815679
  

  After:

  $ RAILS_ENV=test rails dbconsole
  > SELECT * FROM ar_internal_metadata;
  key|value|created_at|updated_at
  environment|test|2017-09-11 23:14:10.815679|2017-09-11 23:14:10.815679
  

  Fixes #26731.

  bogdanvlviv

• Fix longer sequence name detection for serial columns.

  Fixes #28332.

  Ryuta Kamizono

• MySQL: Don't lose auto_increment: true in the db/schema.rb.

  Fixes #30894.

  Ryuta Kamizono

• Fix COUNT(DISTINCT ...) for GROUP BY with ORDER BY and LIMIT.

  Fixes #30886.

  Ryuta Kamizono

• PostgreSQL tsrange now preserves subsecond precision.

  PostgreSQL 9.1+ introduced range types, and Rails added support for using this datatype in Active Record. However, the serialization of PostgreSQL::OID::Range was incomplete, because it did not properly cast the bounds that make up the range. This led to subseconds being dropped in SQL commands:

  Before:

  connection.type_cast(tsrange.serialize(range_value))
  # => "[2010-01-01 13:30:00 UTC,2011-02-02 19:30:00 UTC)"
  

  Now:

  connection.type_cast(tsrange.serialize(range_value))
  # => "[2010-01-01 13:30:00.670277,2011-02-02 19:30:00.745125)"
  

  Thomas Cannon

• Passing a Set to Relation#where now behaves the same as passing an array.

  Sean Griffin

• Use given algorithm while removing index from database.

  Fixes #24190.

  Mehmet Emin İNAÇ

• Update payload names for sql.active_record instrumentation to be more descriptive.

  Fixes #30586.

  Jeremy Green

• Add new error class LockWaitTimeout which will be raised when lock wait timeout exceeded.

  Gabriel Courtemanche

• Remove deprecated #migration_keys.

  Ryuta Kamizono

• Automatically guess the inverse associations for STI.

  Yuichiro Kaneko

• Ensure sum honors distinct on has_many :through associations

  Fixes #16791.

  Aaron Wortham

• Add binary fixture helper method.

  Atsushi Yoshida

• When using Relation#or, extract the common conditions and put them before the OR condition.

  Maxime Handfield Lapointe

• Relation#or now accepts two relations who have different values for references only, as references can be implicitly called by where.

  Fixes #29411.

  Sean Griffin

• ApplicationRecord is no longer generated when generating models. If you need to generate it, it can be created with rails g application_record.

  Lisa Ugray

• Fix COUNT(DISTINCT ...) with ORDER BY and LIMIT to keep the existing select list.

  Ryuta Kamizono

• When a has_one association is destroyed by dependent: destroy, destroyed_by_association will now be set to the reflection, matching the behaviour of has_many associations.

  Lisa Ugray

• Fix unscoped(where: [columns]) removing the wrong bind values

  When the where is called on a relation after a or, unscoping the column of that later where removed bind values used by the or instead. (possibly other cases too)

  Post.where(id: 1).or(Post.where(id: 2)).where(foo: 3).unscope(where: :foo).to_sql
  # Currently:
  #     SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 2 OR "posts"."id" = 3)
  # With fix:
  #     SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 1 OR "posts"."id" = 2)
  

  Maxime Handfield Lapointe

• Values constructed using multi-parameter assignment will now use the post-type-cast value for rendering in single-field form inputs.

  Sean Griffin

• Relation#joins is no longer affected by the target model's current_scope, with the exception of unscoped.

  Fixes #29338.

  Sean Griffin

• Change sqlite3 boolean serialization to use 1 and 0

  SQLite natively recognizes 1 and 0 as true and false, but does not natively recognize 't' and 'f' as was previously serialized.

  This change in serialization requires a migration of stored boolean data for SQLite databases, so it's implemented behind a configuration flag whose default false value is deprecated.

  Lisa Ugray

• Skip query caching when working with batches of records (find_each, find_in_batches, in_batches).

  Previously, records would be fetched in batches, but all records would be retained in memory until the end of the request or job.

  Eugene Kenny

• Prevent errors raised by sql.active_record notification subscribers from being converted into ActiveRecord::StatementInvalid exceptions.

  Dennis Taylor

• Fix eager loading/preloading association with scope including joins.

  Fixes #28324.

  Ryuta Kamizono

• Fix transactions to apply state to child transactions

  Previously, if you had a nested transaction and the outer transaction was rolledback, the record from the inner transaction would still be marked as persisted.

  This change fixes that by applying the state of the parent transaction to the child transaction when the parent transaction is rolledback. This will correctly mark records from the inner transaction as not persisted.

  Eileen M. Uchitelle, Aaron Patterson

• Deprecate set_state method in TransactionState

  Deprecated the set_state method in favor of setting the state via specific methods. If you need to mark the state of the transaction you can now use rollback!, commit! or nullify! instead of set_state(:rolledback), set_state(:committed), or set_state(nil).

  Eileen M. Uchitelle, Aaron Patterson

• Deprecate delegating to arel in Relation.

  Ryuta Kamizono

• Query cache was unavailable when entering the ActiveRecord::Base.cache block without being connected.

  Tsukasa Oishi

• Previously, when building records using a has_many :through association, if the child records were deleted before the parent was saved, they would still be persisted. Now, if child records are deleted before the parent is saved on a has_many :through association, the child records will not be persisted.

  Tobias Kraze

• Merging two relations representing nested joins no longer transforms the joins of the merged relation into LEFT OUTER JOIN. Example to clarify:

  Author.joins(:posts).merge(Post.joins(:comments))
  # Before the change:
  #=> SELECT ... FROM authors INNER JOIN posts ON ... LEFT OUTER JOIN comments ON...
  
  # After the change:
  #=> SELECT ... FROM authors INNER JOIN posts ON ... INNER JOIN comments ON...
  

  TODO: Add to the Rails 5.2 upgrade guide

  Maxime Handfield Lapointe

• ActiveRecord::Persistence#touch does not work well when optimistic locking enabled and locking_column, without default value, is null in the database.

  bogdanvlviv

• Fix destroying existing object does not work well when optimistic locking enabled and locking_column is null in the database.

  bogdanvlviv

• Use bulk INSERT to insert fixtures for better performance.

  Kir Shatrov

• Prevent creation of bind param if casted value is nil.

  Ryuta Kamizono

• Deprecate passing arguments and block at the same time to count and sum in ActiveRecord::Calculations.

  Ryuta Kamizono

• Loading model schema from database is now thread-safe.

  Fixes #28589.

  Vikrant Chaudhary, David Abdemoulaie

• Add ActiveRecord::Base#cache_version to support recyclable cache keys via the new versioned entries in ActiveSupport::Cache. This also means that ActiveRecord::Base#cache_key will now return a stable key that does not include a timestamp any more.

  NOTE: This feature is turned off by default, and #cache_key will still return cache keys with timestamps until you set ActiveRecord::Base.cache_versioning = true. That's the setting for all new apps on Rails 5.2+

  DHH

• Respect SchemaDumper.ignore_tables in rake tasks for databases structure dump

  Rusty Geldmacher, Guillermo Iguaran

• Add type caster to RuntimeReflection#alias_name

  Fixes #28959.

  Jon Moss

• Deprecate supports_statement_cache?.

  Ryuta Kamizono

• Raise error UnknownMigrationVersionError on the movement of migrations when the current migration does not exist.

  bogdanvlviv

• Fix bin/rails db:forward first migration.

  bogdanvlviv

• Support Descending Indexes for MySQL.

  MySQL 8.0.1 and higher supports descending indexes: DESC in an index definition is no longer ignored. See https://dev.mysql.com/doc/refman/8.0/en/descending-indexes.html.

  Ryuta Kamizono

• Fix inconsistency with changed attributes when overriding Active Record attribute reader.

  bogdanvlviv

• When calling the dynamic fixture accessor method with no arguments, it now returns all fixtures of this type. Previously this method always returned an empty array.

  Kevin McPhillips

Please check 5-1-stable for previous changes.