Only add a error messages for one model attribute if this error message not exists for the model attribute

Simplifies sending notifications to your end users through multiple channels

Instruments all activerecord objects with notifications around callbacks

Provides a set of helper methods for dealing with chronological records that have common primary key and date columns denoting when the record is active (example: Oracle EBS tables).

Provides the method of 'clone_ar' that can clone your current object. \ Accepts options on both class level and method call level.

Loading up TEXT/BLOB columns can be slow

Helping functionality for filtering, sorting and stuff like that with data-tables and ActiveRecord.

ActiveRecord generator and RSpec templates that add some basic functionality to the model and its spec

map activerecord models to tables depending on context

If you are stuck with a MySQL database where the naming is, well, unrailslike, activerecord-mysql2-legacy-db-adapter offers a way to do the translation. It works at the driver level and doesn't require you ro change the structure of the database. Also there are no database views which should be kept up to date as you add or remove fields.

Oracle enhanced adapter with schema config support for ActiveRecord (Using this gem, you can specify schema details in database.yml). This gem is a tweaked version of original activerecord-oracle_enhanced-adapter gem.

ActiveRecord support for PostgreSQL JSON type supporting Rails 4.0-4.1

Using an ActiveRecord scope, recursively query trees.

For data records that only need to be partially updated, this provides versioning for dirty attributes

Stream ActiveRecord results

This tool allows you to generate quick and simple Excel reports based on the array of records returned by your ActiveRecord queries

It sends ActiveRecord objets to SimpleDB using Resque

Queue up calls to specific models and execute them in transactions, after a certain number of models have been added.

ActiveRecord adapter for Vertica databaes

A method that allows you to run code without callbacks for a specific active-record model.