CHANGELOG.md

• Skip optimised #exist? query when #include? is called on a relation with a having clause

  Relations that have aliased select values AND a having clause that references an aliased select value would generate an error when #include? was called, due to an optimisation that would generate call #exists? on the relation instead, which effectively alters the select values of the query (and thus removes the aliased select values), but leaves the having clause intact. Because the having clause is then referencing an aliased column that is no longer present in the simplified query, an ActiveRecord::InvalidStatement error was raised.

  An sample query affected by this problem:

  Author.select('COUNT(*) as total_posts', 'authors.*')
        .joins(:posts)
        .group(:id)
        .having('total_posts > 2')
        .include?(Author.first)

  This change adds an addition check to the condition that skips the simplified #exists? query, which simply checks for the presence of a having clause.

  Fixes #41417

  Michael Smart

• Increment postgres prepared statement counter before making a prepared statement, so if the statement is aborted without Rails knowledge (e.g., if app gets kill -9d during long-running query or due to Rack::Timeout), app won't end up in perpetual crash state for being inconsistent with Postgres.

  wbharding, Martin Tepper

• Add ability to apply scoping to all_queries.

  Some applications may want to use the scoping method but previously it only worked on certain types of queries. This change allows the scoping method to apply to all queries for a model in a block.

  Post.where(blog_id: post.blog_id).scoping(all_queries: true) do
    post.update(title: "a post title") # adds `posts.blog_id = 1` to the query
  end

  Eileen M. Uchitelle

• Switch to database adapter return type for ActiveRecord::Calculations.calculate when called with :average (aliased as ActiveRecord::Calculations.average)

  Previously average aggregation returned BigDecimal for everything which supported to_d. This was especially weird for floating point numbers.

  Database adapters today map database column types to Ruby types more accurately than 10 years ago. So now we simply pass them on (except for special cases which are not Numeric).

  # With the following schema:
  create_table "measurements" do |t|
    t.float "temperature"
  end
  
  # Before:
  Measurement.average(:temperature).class
  # => BigDecimal
  
  # After:
  Measurement.average(:temperature).class
  # => Float

  Josua Schmid

• PostgreSQL: handle timestamp with time zone columns correctly in schema.rb.

  Previously they dumped as t.datetime :column_name, now they dump as t.timestamptz :column_name, and are created as timestamptz columns when the schema is loaded.

  Alex Ghiculescu

• Add ActiveRecord::Base.connection.with_advisory_lock.

  This method allow applications to obtain an exclusive session level advisory lock, if available, for the duration of the block.

  If another session already have the lock, the method will return false and the block will not be executed.

  Rafael Mendonça França

• Removing trailing whitespace when matching columns in ActiveRecord::Sanitization.disallow_raw_sql!.

  Gannon McGibbon, Adrian Hirt

• Expose a way for applications to set a primary_abstract_class

  Multiple database applications that use a primary abstract class that is not named ApplicationRecord can now set a specific class to be the primary_abstract_class.

  class PrimaryApplicationRecord
    self.primary_abstract_class
  end

  When an application boots it automatically connects to the primary or first database in the database configuration file. In a multiple database application that then call connects_to needs to know that the default connection is the same as the ApplicationRecord connection. However some applications have a differently named ApplicationRecord. This prevents Active Record from opening duplicate connections to the same database.

  Eileen M. Uchitelle, John Crepezzi

• Support hash config for structure_dump_flags and structure_load_flags flags Now that Active Record supports multiple databases configuration we need a way to pass specific flags for dump/load databases since the options are not the same for different adapters. We can use in the original way:

  ActiveRecord::Tasks::DatabaseTasks.structure_dump_flags = ['--no-defaults', '--skip-add-drop-table']
  #or
  ActiveRecord::Tasks::DatabaseTasks.structure_dump_flags = '--no-defaults --skip-add-drop-table'

  And also use it passing a hash, with one or more keys, where the key is the adapter

  ActiveRecord::Tasks::DatabaseTasks.structure_dump_flags = {
    mysql2: ['--no-defaults', '--skip-add-drop-table'],
    postgres: '--no-tablespaces'
  }

  Gustavo Gonzalez

• Connection specification now passes the "url" key as a configuration for the adapter if the "url" protocol is "jdbc", "http", or "https". Previously only urls with the "jdbc" prefix were passed to the Active Record Adapter, others are assumed to be adapter specification urls.

  Fixes #41137.

  Jonathan Bracy

• Allow to opt-out of strict_loading mode on a per-record base.

  This is useful when strict loading is enabled application wide or on a model level.

  class User < ApplicationRecord
    has_many :bookmarks
    has_many :articles, strict_loading: true
  end
  
  user = User.first
  user.articles                        # => ActiveRecord::StrictLoadingViolationError
  user.bookmarks                       # => #<ActiveRecord::Associations::CollectionProxy>
  
  user.strict_loading!(true)           # => true
  user.bookmarks                       # => ActiveRecord::StrictLoadingViolationError
  
  user.strict_loading!(false)          # => false
  user.bookmarks                       # => #<ActiveRecord::Associations::CollectionProxy>
  user.articles.strict_loading!(false) # => #<ActiveRecord::Associations::CollectionProxy>

  Ayrton De Craene

• Add FinderMethods#sole and #find_sole_by to find and assert the presence of exactly one record.

  Used when you need a single row, but also want to assert that there aren't multiple rows matching the condition; especially for when database constraints aren't enough or are impractical.

  Product.where(["price = %?", price]).sole
  # => ActiveRecord::RecordNotFound      (if no Product with given price)
  # => #<Product ...>                    (if one Product with given price)
  # => ActiveRecord::SoleRecordExceeded  (if more than one Product with given price)
  
  user.api_keys.find_sole_by(key: key)
  # as above

  Asherah Connor

• Makes ActiveRecord::AttributeMethods::Query respect the getter overrides defined in the model.

  Before:

  class User
    def admin
      false # Overriding the getter to always return false
    end
  end
  
  user = User.first
  user.update(admin: true)
  
  user.admin # false (as expected, due to the getter overwrite)
  user.admin? # true (not expected, returned the DB column value)

  After this commit, user.admin? above returns false, as expected.

  Fixes #40771.

  Felipe

• Allow delegated_type to be specified primary_key and foreign_key.

  Since delegated_type assumes that the foreign_key ends with _id, singular_id defined by it does not work when the foreign_key does not end with id. This change fixes it by taking into account primary_key and foreign_key in the options.

  Ryota Egusa

• Expose an invert_where method that will invert all scope conditions.

  class User
    scope :active, -> { where(accepted: true, locked: false) }
  end
  
  User.active
  # ... WHERE `accepted` = 1 AND `locked` = 0
  
  User.active.invert_where
  # ... WHERE NOT (`accepted` = 1 AND `locked` = 0)

  Kevin Deisz

• Restore possibility of passing false to :polymorphic option of belongs_to.

  Previously, passing false would trigger the option validation logic to throw an error saying :polymorphic would not be a valid option.

  glaszig

• Remove deprecated database kwarg from connected_to.

  Eileen M. Uchitelle, John Crepezzi

• Allow adding nonnamed expression indexes to be revertible.

  Fixes #40732.

  Previously, the following code would raise an error, when executed while rolling back, and the index name should be specified explicitly. Now, the index name is inferred automatically.

  add_index(:items, "to_tsvector('english', description)")

  fatkodima

• Only warn about negative enums if a positive form that would cause conflicts exists.

  Fixes #39065.

  Alex Ghiculescu

• Add option to run default_scope on all queries.

  Previously, a default_scope would only run on select or insert queries. In some cases, like non-Rails tenant sharding solutions, it may be desirable to run default_scope on all queries in order to ensure queries are including a foreign key for the shard (ie blog_id).

  Now applications can add an option to run on all queries including select, insert, delete, and update by adding an all_queries option to the default scope definition.

  class Article < ApplicationRecord
    default_scope -> { where(blog_id: Current.blog.id) }, all_queries: true
  end

  Eileen M. Uchitelle

• Add where.associated to check for the presence of an association.

  # Before:
  account.users.joins(:contact).where.not(contact_id: nil)
  
  # After:
  account.users.where.associated(:contact)

  Also mirrors where.missing.

  Kasper Timm Hansen

• Allow constructors (build_association and create_association) on has_one :through associations.

  Santiago Perez Perret

Please check 6-1-stable for previous changes.