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.

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

Ferry is a data migration and visualization command line tool rubygem that seeks to simplify the increasingly prevalent big data problems for developers

Adds missing native PostgreSQL data types to ActiveRecord and convenient querying extensions for ActiveRecord and Arel

Build complex SQL queries by defining each subquery separately. Query::Composer will then compose those subqueries together, nesting as needed, to produce the final SQL query.

ActiveRecord adapter for Crate, the distributed database for Docker.

This gem provides the Rails 3 with database adapter for AWS RedShift.

Convert MongoDB query to Arel for PostgreSQL + JSON

Generates action methods to provide clean tables.

ActiveRecord Amazon Timestream Adapter

Just an ActiveRecord Adapter for the Appengine Datastore. Create Rails3 application: rails new app_name -m http://siddick.github.com/datastore/rails3.rb

An ActiveRecord extension for enabling SQL_CACHE and SQL_NO_CACHE in MySQL queries

Add index hint to MySQL query in Arel.

Flounder is the missing piece between the database and your Ruby code. It allows very simple access to database tables without going all the way to begin an object mapper.

Makes it easy to set a role strategy on your User model in Active Record

Simply conditions DSL for ActiveRecord

Hive adapter for ActiveRecord

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.

Fork of SQL Server 2005 and 2008 Adapter For ActiveRecord. Adds support for SQL Server 2000.

SQL Server 2005 and 2008 Adapter For ActiveRecord. Forked in order to disable unicode.