rails/activerecord/CHANGELOG.md

• Inverse association instances will now be set before after_find or after_initialize callbacks are run.

  Fixes #26320.

  Sean Griffin

• Remove unnecessarily association load when a belongs_to association has already been loaded then the foreign key is changed directly and the record saved.

  James Coleman

• Remove standardized column types/arguments spaces in schema dump.

  Tim Petricola

• Avoid loading records from database when they are already loaded using the pluck method on a collection.

  Fixes #25921.

  Ryuta Kamizono

• Remove text default treated as an empty string in non-strict mode for consistency with other types.

  Strict mode controls how MySQL handles invalid or missing values in data-change statements such as INSERT or UPDATE. If strict mode is not in effect, MySQL inserts adjusted values for invalid or missing values and produces warnings.

  def test_mysql_not_null_defaults_non_strict
    using_strict(false) do
      with_mysql_not_null_table do |klass|
        record = klass.new
        assert_nil record.non_null_integer
        assert_nil record.non_null_string
        assert_nil record.non_null_text
        assert_nil record.non_null_blob
  
        record.save!
        record.reload
  
        assert_equal 0,  record.non_null_integer
        assert_equal "", record.non_null_string
        assert_equal "", record.non_null_text
        assert_equal "", record.non_null_blob
      end
    end
  end
  

  https://dev.mysql.com/doc/refman/5.7/en/sql-mode.html#sql-mode-strict

  Ryuta Kamizono

• Sqlite3 migrations to add a column to an existing table can now be successfully rolled back when the column was given and invalid column type.

  Fixes #26087

  Travis O'Neill

• Deprecate sanitize_conditions. Use sanitize_sql instead.

  Ryuta Kamizono

• Doing count on relations that contain LEFT OUTER JOIN Arel node no longer force a DISTINCT. This solves issues when using count after a left_joins.

  Maxime Handfield Lapointe

• RecordNotFound raised by association.find exposes id, primary_key and model methods to be consistent with RecordNotFound raised by Record.find.

  Michel Pigassou

• Hashes can once again be passed to setters of composed_of, if all of the mapping methods are methods implemented on Hash.

  Fixes #25978.

  Sean Griffin

• Fix the SELECT statement in #table_comment for MySQL.

  Takeshi Akima

• Virtual attributes will no longer raise when read on models loaded from the database

  Sean Griffin

• Support calling the method merge in scope's lambda.

  Yasuhiro Sugino

• Fixes multi-parameter attributes conversion with invalid params.

  Hiroyuki Ishii

• Add newline between each migration in structure.sql.

  Keeps schema migration inserts as a single commit, but allows for easier git diffing.

  Fixes #25504.

  Grey Baker, Norberto Lopes

• The flag error_on_ignored_order_or_limit has been deprecated in favor of the current error_on_ignored_order.

  Xavier Noria

• Batch processing methods support limit:

  Post.limit(10_000).find_each do |post|
    # ...
  end
  

  It also works in find_in_batches and in_batches.

  Xavier Noria

• Using group with an attribute that has a custom type will properly cast the hash keys after calling a calculation method like count.

  Fixes #25595.

  Sean Griffin

• Fix the generated #to_param method to use omission: '' so that the resulting output is actually up to 20 characters, not effectively 17 to leave room for the default "...". Also call #parameterize before #truncate and make the separator: /-/ to maximize the information included in the output.

  Fixes #23635.

  Rob Biedenharn

• Ensure concurrent invocations of the connection reaper cannot allocate the same connection to two threads.

  Fixes #25585.

  Matthew Draper

• Inspecting an object with an associated array of over 10 elements no longer truncates the array, preventing inspect from looping infinitely in some cases.

  Kevin McPhillips

• Removed the unused methods ActiveRecord::Base.connection_id and ActiveRecord::Base.connection_id=.

  Sean Griffin

• Ensure hashes can be assigned to attributes created using composed_of.

  Fixes #25210.

  Sean Griffin

• Fix logging edge case where if an attribute was of the binary type and was provided as a Hash.

  Jon Moss

• Handle JSON deserialization correctly if the column default from database adapter returns '' instead of nil.

  Johannes Opper

• Introduce ActiveRecord::TransactionSerializationError for catching transaction serialization failures or deadlocks.

  Erol Fornoles

• PostgreSQL: Fix db:structure:load silent failure on SQL error.

  The command line flag -v ON_ERROR_STOP=1 should be used when invoking psql to make sure errors are not suppressed.

  Example:

  psql -v ON_ERROR_STOP=1 -q -f awesome-file.sql my-app-db
  

  Fixes #23818.

  Ralin Chimev

Please check 5-0-stable for previous changes.