rails--rails/activerecord/CHANGELOG.md

• When a table has a composite primary key, the primary_key method for SQLite3 and PostgreSQL adapters was only returning the first field of the key. Ensures that it will return nil instead, as Active Record doesn't support composite primary keys.

  Fixes #18070.

  arthurnn

• validates_size_of / validates_length_of do not count records, which are marked_for_destruction?.

  Fixes #7247.

  Yves Senn

• Ensure first! and friends work on loaded associations.

  Fixes #18237.

  Sean Griffin

• eager_load preserves readonly flag for associations.

  Closes #15853.

  Takashi Kokubun

• Provide :touch option to save() to accommodate saving without updating timestamps.

  Fixes #18202.

  Dan Olson

• Provide a more helpful error message when an unsupported class is passed to serialize.

  Fixes #18224.

  Sean Griffin

• Add bigint primary key support for MySQL.

  Example:

  create_table :foos, id: :bigint do |t|
  end
  

  Ryuta Kamizono

• Support for any type primary key.

  Fixes #14194.

  Ryuta Kamizono

• Dump the default nil for PostgreSQL UUID primary key.

  Ryuta Kamizono

• Add a :foreign_key option to references and associated migration methods. The model and migration generators now use this option, rather than the add_foreign_key form.

  Sean Griffin

• Don't raise when writing an attribute with an out-of-range datetime passed by the user.

  Grey Baker

• Replace deprecated ActiveRecord::Tasks::DatabaseTasks#load_schema with ActiveRecord::Tasks::DatabaseTasks#load_schema_for.

  Yves Senn

• Fixes bug with 'ActiveRecord::Type::Numeric' that causes negative values to be marked as having changed when set to the same negative value.

  Closes #18161.

  Daniel Fox

• Introduce force: :cascade option for create_table. Using this option will recreate tables even if they have dependent objects (like foreign keys). db/schema.rb now uses force: :cascade. This makes it possible to reload the schema when foreign keys are in place.

  Matthew Draper, Yves Senn

• db:schema:load and db:structure:load no longer purge the database before loading the schema. This is left for the user to do. db:test:prepare will still purge the database.

  Closes #17945.

  Yves Senn

• Fix undesirable RangeError by Type::Integer. Add Type::UnsignedInteger.

  Ryuta Kamizono

• Add foreign_type option to has_one and has_many association macros.

  This option enables to define the column name of associated object's type for polymorphic associations.

  Ulisses Almeida, Kassio Borges

• Remove deprecated behavior allowing nested arrays to be passed as query values.

  Melanie Gilman

• Deprecate passing a class as a value in a query. Users should pass strings instead.

  Melanie Gilman

• add_timestamps and remove_timestamps now properly reversible with options.

  Noam Gagliardi-Rabinovich

• ActiveRecord::ConnectionAdapters::ColumnDumper#column_spec and ActiveRecord::ConnectionAdapters::ColumnDumper#prepare_column_options no longer have a types argument. They should access connection#native_database_types directly.

  Yves Senn

Please check 4-2-stable for previous changes.