News

.NET Entity Framework Slips Beyond Orcas

• By Kathleen Richards
• April 30, 2007

The Entity Framework is now expected in the first half of 2008 as an Orcas extension to the .NET Framework, according to Microsoft blogger Mike Pizzo, an architect with the Data Programmability team.

The news comes just nine days after Microsoft released Orcas Beta 1, which includes Entity Framework functionality.

The Entity Framework is a data-access technology that builds on top of ADO.NET 2.0. It uses the Entity Relational Model (the "Entity Data Model" in Microsoft terminology) to create conceptual models of data before the data is mapped into relational schemas. This allows developers to program against a conceptual domain model instead of the relational database layer.

The Entity Framework shipped as part of Orcas Beta 1; however, key functionality needed to make use of the framework practical, specifically the Entity Data Model Designer, had already slipped beyond the 'Orcas' RTM, according to an earlier announcement by Microsoft. The plan now is to release Entity Framework Community Technology Previews and Betas that align with Orcas, according to Pizzo.

Roger Jennings, a developer and technology writer for OakLeaf Systems, doesn't think the later ship date is going to be a big deal. "They decided that they couldn't release the Entity Framework without the Entity Data Model Designer, which was my contention to start with," he said. "And they've also just announced a couple of incubation projects that depend on it that also might have an influence on the delivery date." (Find out more about the Data Access incubation projects on Jennings' blog and MSDN.)

"It's good that they are holding off; if they feel as though it isn't right and won't be useful, then that's a great thing," said Don Demsak, an independent consultant based in New Jersey who focuses on Microsoft's Language Integrated Query (LINQ), XML and related technologies. "It will give people time to focus on the other aspects of LINQ before the 'big kahuna' comes in."

In spite of the Entity Framework slip, Visual Studio "Orcas" will still offer a lot of new data awareness functionality enabled by the LINQ extensions, which require .NET FX 3.5. Pizzo explained the planned LINQ functionality in his blog.

"At the time that Orcas first ships, the .NET Framework will include support for LINQ over in-memory objects, LINQ over XML (XLINQ), LINQ over ADO.NET DataSets (LINQ to DataSet), and LINQ queries directly mapped to Microsoft SQL Server schemas (LINQ to SQL)."

The LINQ to Entities extension, which will enable developers to use LINQ to query relational data stores supported by ADO.NET providers, will ship at the same time as the Entity Framework, according to Pizzo.

Many of the people who worked on Microsoft's ill-fated ObjectSpaces project, which tackled object to relational mapping in .NET in Visual Studio 2005, are involved in the Entity Framework development. Microsoft released ObjectSpaces as a beta, but it never made it to RTM. "They were trying to do too much to please too many people and it just never shipped," recalls Demsak.

"Almost everybody is considering [Entity Framework] to be ObjectSpaces revisited, but I don't think that's the case," says Jennings.

With all the LINQ enhancements in Orcas, especially LINQ to XML and LINQ to SQL, developers should be fine, commented Demsak.