== 2.0.8 / 2010/02/08
* Bug Fixes
* Added set operation support
* Fixed problems with *_any / *_all methods.
== 2.0.7 (unreleased)
* Bug Fixes
* Limit members are visited
* Fixing MSSQL TOP support
== 2.0.6 12/01/2010
* Bug Fixes
* Rails 3.0.x does not like that Node is Enumerable, so removing for now.
== 2.0.5 11/30/2010
* Enhancements
* Arel::Visitors::DepthFirst can walk your AST depth first
* Arel::Nodes::Node is enumerable, depth first
* Bug fixes
* #lock will lock SELECT statements "FOR UPDATE" on mysql
* Nodes::Node#not factory method added for creating Nodes::Not nodes
* Added an As node
* Deprecations
* Support for Subclasses of core classes will be removed in ARel version
2.2.0
== 2.0.4
* Bug fixes
* Speed improvements for Range queries. Thanks Rolf Timmermans!
== 2.0.3
* Bug fixes
* Fixing Oracle support
* Added a visitor for "Class" objects
== 2.0.2
* Bug fixes
* MySQL selects from DUAL on empty FROM
* Visitor translates nil to NULL
* Visitor translates Bignum properly
== 2.0.1
* Bug fixes
== 2.0.0 / 2010-08-01
* Enhancements
* Recreate library using the Visitor pattern.
http://en.wikipedia.org/wiki/Visitor_pattern
## Abstract ##
Arel is a Relational Algebra for Ruby.
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.
## Status ##
For the moment, Arel uses ActiveRecord's connection adapters to
connect to the various engines, connection pooling, perform quoting,
and do type conversion. On the horizon is the use of DataObjects
instead.
The long term goal, following both LINQ and DataMapper, is to have
Arel adapt to engines beyond RDBMS, including XML, IMAP, YAML, etc.
