Redmond Releases ADO.NET Beta 2
Anticipated second beta of ADO.NET Entity Framework released.
Microsoft in late August released beta 2 of its ADO.NET Entity Framework and with it, the much-anticipated first beta of the Entity Designer community technology preview and related tooling, which was missing from beta 1.
First announced a year ago, the Entity Framework is an object-relational mapping technology within the ADO.NET components of the .NET Framework. It's designed to allow developers to work at the conceptual schema layer (the application), rather than at the logical schema layer (the tables and columns of a relational database). Explains Roger Jennings, principal consultant at Northern California-based software consulting organization OakLeaf Systems, the framework allows developers to focus on building apps without worrying about the physical storage of data.
"On a basic level, the Entity Framework is an object-relational mapping tool," Jennings tells RDN. "That was its original purpose. Microsoft is emphasizing its ability to map from the physical model of the database to the conceptual model of the application."
Entity Framework supports a provider-agnostic approach to data, allowing developers to build applications on top of any data source. It employs the Entity Data Model, which is designed to enable applications to expose data as a data service that can be consumed by Web clients.
"The Entity Data Model is just a more sophisticated, more layered approach to object-relational mapping," Jennings says. "Microsoft concentrated most of its initial efforts on getting the initial layers right -- conceptual schema, mapping data layer, and the logical data layer. They put a lot of effort into that, in some respects to the detriment of the remainder of the mapping. They also developed a special dialect of SQL called Entity SQL, which is suited to querying entities, as opposed to querying relational tables. It's very close to SQL."
Jennings expects database developers to do a lot of tire kicking during this beta release, and even when version 1 is released. But he predicts that widespread enterprise adoption will wait for version 2. For one thing, it lacks complete "persistence ignorance" (a label coined by author Martin Fowler), which describes a domain layer containing entities that are unaware of the underlying persistence mechanism. "It's something enterprise developers are going to want to have," Jennings says.
Daniel Simmons, a developer lead on Microsoft's ADO.NET team, responded to this issue on his blog, stating, "The team is now working on a series of product changes aimed at ensuring that a later move to complete persistence ignorance will not be a fundamental breaking change."