Arel is a SQL AST manager for Ruby. It 1. Simplifies the generation complex of SQL queries 2. Adapts to various RDBMS systems It is intended to be a framework framework; that is, you can build your own ORM with it, focusing on innovative object and collection modeling as opposed to database compatibility and query generation.
Gemfile gem 'arel', '~> 2.1.4'
install gem install arel -v 2.1.4