Quite a bit of activity last week in the Visual Studio and ORM spaces.
Visual Studio released a CTP of Visual Studio 2008 support for SQL Server 2008 CTP6. It allows you to connect to CTP6 with Server Explorer, which enables quite a few other features to work. check with Overview document on the download page. SQLCLR projects and T-SQL and SQLCLR debugging work too.
Curiously the Overview document says "using the LINQ to SQL Designer with SQL Server 2008 databases" is specifically not supported. But I've used SQL Server 2008 WITH NO new data types (e.g. DATE, TIME, etc) and it does seems to work. EF beta3 designer too. Maybe they are referring to lack of support for the new data types. Speaking of which…
Faisal Mohamood announced on the ADO.NET team blog that they ARE working on support for the four new date and time types in SQL Server 2008. Hooray. Now let's keep our fingers crossed for SQL Server UDT support.
Julie Lerman wants these types in EF too, but I'm not sure I agree. DATE and TIME would be nice because they're ANSI standard types. DATETIME2 maps favorably to DateTime in EF, actually better coverage of the value space than DATETIME. Maybe what she really means is that she wants the SSDL and MDL and the designer to be aware of them and generate the closest possible mapping. Even if that's "string".
The distinction is that the ADO.NET Entity Framework is meant to be database neutral, not SQL Server specific, and supports a discrete subset of database data types not a 1-1 mapping of EF types to SQL Server types. LINQ to SQL, OTOH, is SQL Server-specific and should support a 1-1 mapping. At this point I'm really thinking they should have called it "LINQ to SQL Server". Not that the *concept* can't be extended to other databases (LINQ to DB2, LINQ to Oracle, etc) but these databases will have to implement their own. The fact is that LINQ to SQLCE does exist and is separate from LINQ to SQL (Server). And other vendors may follow with their own, database-dependent implementation of a light LINQ layer. But speaking of SQLCE…
The SQLCEBLOG announced the beta of SQLCE 3.5 SP1 with ADO.NET Entity Framework Beta 3. There was support for EF in SQLCE a while ago, but it was postponed in the 3.5 release which sports LINQ support. Now it looks like Entity Framework support is back. Hooray. BUT, although a common programming model between SQLCE and a subset of SQL Server functionality is a great idea, IMHO the best and most lightweight programming model for SQLCE uses SqlResultset. Still the winner.
Oh yes, BTW, SQL Sevrer 2008 CTP6 was released last week. But that's been posted on EVERY SQL Server related blog in the world. Congrats for another CTP folks. Sparse columns, filtered indexes, and filtered statistics are in as well as quite a few other features.