MetaWhere offers the ability to call any Arel predicate methods (with a few convenient aliases) on your Model's attributes instead of the ones normally offered by ActiveRecord's hash parameters. It also adds convenient syntax for order clauses, smarter mapping of nested hash conditions, and a debug_sql method to see the real SQL your code is generating without running it against the database. If you like the new AR 3.0 query interface, you'll love it with MetaWhere.

RSpec matcher to control SQL queries made by block of code

Scoped search makes it easy to search your ActiveRecord-based models. It will create a named scope :search_for that can be called with a query string. It will build an SQL query using the provided query string and a definition that specifies on what fields to search. Because the functionality is built on named_scope, the result of the search_for call can be used like any other named_scope, so it can be chained with another scope or combined with will_paginate. Because it uses standard SQL, it does not require any setup, indexers or daemons. This makes scoped_search suitable to quickly add basic search functionality to your application with little hassle. On the other hand, it may not be the best choice if it is going to be used on very large datasets or by a large user base.

ThumbsUp provides dead-simple voting capabilities to ActiveRecord models with karma calculation, a la stackoverflow.com.

Dynamically build a model within an RSpec context

ActiveWarehouse ETL is a pure Ruby Extract-Transform-Load application for loading data into a database.

Extend ActiveRecord pluck to return hash instead of an array. Useful when plucking multiple columns.

Rails extensions for using Roar in the popular web framework.

Make your PG migrations safe.

Create temporary table-backed ActiveRecord models for use in tests

Real PostgreSQL 9.5+ upserts using ON CONFLICT for ActiveRecord

Make your model acts as a list. This acts_as extension provides the capabilities for sorting and reordering a number of objects in a list. The class that has this specified needs to have a +position+ column defined as an integer on the mapped database table.

Execute irreversible actions only when transactions are not rolled back

ActiveRecord provides validations on app level but it won't guarantee the consistent. In some cases, like `validates_uniqueness_of` it executes additional SQL query to the database and that is not very efficient. The main goal of the gem is to provide compatibility between database constraints and ActiveRecord validations with better performance and consistency.

Easy SQL based report generation with the ability to accept request parameters and render multiple formats.

Easily create robust, standardized API endpoints using lightning-fast database queries

A good, simple, solid tagging extension for ActiveRecord

Add social network friendship features to your Active Record models.

Mongify allows you to map your sql data into a mongodb document database with a simple DSL.

Multiple databases for Rails