Version 0.7.3 of restSQL, an open-source persistence framework, was released on January 16, 2012. The release adds adds unlimited SQL Resource table extensions. SQL Resources in previous releases were constrained to a maximum of one parent and one child extension. 0.7.3 enables an SQL Resource to join an abitrary number of tables to create a flat or hierarchical application-specific view.
See http://restsql.org for an overview, developer documentation and binary distributions of the framework and the SDK. The source code is licensed under MIT and hosted on github.
restSQL is a very unconventional, ultra-lightweight data access layer. For many applications, conventional ORM is heavyweight and inflexible, and conventional Web Services (WSDL/SOAP) are cumbersome. restSQL substantially lightens the middle-tier. It is targeted at the 80% of data access that is basic CRUD (Create-Read-Update-Delete), making it faster and simpler to develop distributed applications.
restSQL is not an object-oriented view of the database. It presents flat or hierarchical "views" of relational database tables. These views are query-able and updatable through a simple REST-based HTTP or Java API. The HTTP interface is based on REST principles, which use HTTP's built-in features, rather than abstracting away from them.