ADO.NET team blog : ADO.NET Data Services

VS2010 and .NET Framework 4 Beta 2 Announced!

dpblogs — Tue, 20 Oct 2009 00:56:00 GMT

Visual Studio 2010 and the .NET Framework 4 Beta 2 are now available for download by MSDN subscribers and will available to the rest of the world on Wednesday. Beta 2 as well the VS2010 Launch date of March 22, 2010 were announced this morning on Soma’s blog.

Included in Beta 2 are some great new features and updates for the Entity Framework 4 and ADO.NET Data Services 4.

Entity Framework 4 Beta 2

In addition to all of the new EF 4 features that were included in Beta 1, Beta 2 also includes:

Foreign Keys: EF 4 now includes a new type of associations (Foreign Key Associations) that allow you to have Foreign Key properties on your entities. Foreign Key Associations simplify some key scenarios such as Data binding and can be included or excluded when using the model creation and update wizards. Independent Associations supported in .NET 3.5 remain as is, but Foreign Key Associations become the default type of association going forward. Referential integrity constraints can now be created from the designer.
Improvements to POCO Support: Fix-up of changes to navigation properties and FKs is now performed automatically on DetectChanges and SaveChanges. It is also now possible to declare collections as ISet<T> in POCO objects. When either ICollection<T> or ISet<T> is used, the default collection type materialized is HashSet<T>, which among other advantages does not allow duplicate entries.
Lazy Loading on by Default in new Models: When you create a new model in VS 2010, you get generated ObjectContext types that have lazy loading turned on by default (context.ContextOptions.LazyLoadingEnabled = true is placed in the constructor). This simplifies the default experience of working with objects. Of course, it is still possible to turn it off and do explicit and eager loading.
EntityDataSource support for Query Extenders and POCO: EntityDataSource now includes support for ASP.NET Query Extenders and POCO entities. Query Extenders are a new addition to ASP.NET that allow you to have more control over the data retrieval query of a Data Source, leveraging the LINQ capabilities of Entity Framework.
Support for Binary Keys: The EF now allows you to have binary property types (and varbinary storage columns) mapped as Entity Key / Foreign Key.
ObjectMaterialized event: It is now possible to write logic that is executed immediately after an object has been materialized. This event is raised after the scalar, complex and reference properties are populated (collections are filled afterwards).
Object Services API improvements to enable N-Tier and Self Tracking Entities: ObjectStateEntry.GetUpdatableOriginalValues method provides a access to an updatable data record that you can use to establish the original state of an entity at the property level.
Improvements to the generated SQL: Numerous simplifications and improvements of the SQL generated when querying using the Entity Framework have been done including: removal of joins, better translation of certain functions, elimination of constants used for internal purposes, which results in removing of levels of nesting and others.
Navigation Property Management: Users can now delete and add navigation properties, enabling the creation of one-way associations.
Improved Database Generation: SQL CE support has been added. In addition, customization of database generation is significantly simpler now, with the ability to specify the DDL generation template to be used, as well as automatic discovery of installed database generation workflows and templates.
New Extensibility APIs: New APIs enable users to add custom properties to any object in the model and have those properties show up in the property sheet. In addition, other extension points allow for customization of models on load, save, and after the model creation and update wizards run.
Generation of Complex Types from Stored Procedures: When creating a function import from a function, the UI can now detect the columns returned from a stored procedure and create a corresponding complex type. In addition, existing complex types can be updated when a stored procedure definition changes.
Greatly Improved Facet Management: The designer can now distinguish between empty and blank values, and various property facet defaults are handled more cleanly and consistently.
LINQ to Entities improvements: Support for recognizing additional patterns in queries, simplification of EntityFunctions and SqlFunctions static classes and OrderBy is now lifted over filters and other operations.

ADO.NET Data Services 4 Beta 2

Projections: This ADO.NET Data Services URI format has been extended to express projections (i.e. you can now work with a subset of the properties of an entity). Beta 2 includes both server and client library (including LINQ support) support for projections.
Data Binding: The data services client library for the .NET Framework 3.5 SP1 and Silverlight2 has been extended to support two-way data binding for WPF and Silverlight based applications.
Row Count: One scenario we heard a ton of feedback on after shipping V1 of ADO.NET Data Services in the .NET Framework 3.5SP1 is the ability for the a client of a data service to determine the total number of entities in a set without having to retrieve them all. To address this need, we have extended the data services addressing scheme to allow a client to obtain this type of information without having to download all the entities in a set.
Feed Customization (aka "Web Friendly Feeds"): A common ask we have received is to provide the ability to customize how entities are mapped into the various elements of an AtomPub feed. This feature does just that by providing a data service author declarative control over how the data service runtime maps the properties of an entity (e.g. a Customer, Order, etc) to the elements of a feed.
Server Driven Paging (SDP): This one is best described by example. If you had a data service that exposes photos, you likely want to limit the total number of photos a single request to the service can retrieve because the total collection of photos may be very large. This feature allows a service author to set per collection limits on the total number of entities returned for each request. In addition to limiting the number of photos returned per request, the server provides the client a "next link" which is simply a URI specifying how to continue retrieving the rest of the entities in the collection not returned by the first request. For those familiar with AtomPub, this feature adds support for AtomPub <link rel="next" ...> elements to the data service runtime.
Enhanced BLOB Support: This feature enhances the BLOB support provided in V1 to enable data services to stream arbitrarily large BLOBs, store binary content separate from its metadata, easily defer the loading of BLOB content when its metadata is requested, etc.
Request Pipeline: We have started to expose events throughout the data services server request processing pipeline. For this release we’ll expose request level events and in future we’ll look to expose more fine grained events based on your feedback. The goal of exposing our processing pipeline is to allow services further transparency into a data service such that a service author can do things such as setting HTTP response cache headers, wrapping interceptor processing and data service request processing in a single transaction, etc.
New "Data Service Provider" Interface for Custom Provider Writers: As the data services runtime has evolved, so has the number of ways people want to plug data into the data service framework. In V1, two methods (Entity Framework and arbitrary .NET classes) were supported to enable a data service to interact with various diverse data sources. To address another class of environments and data sources we have introduced a way to write a "custom" provider for those cases when the previous two provider models don't meet your needs.

Thank you,

Elisa Flasko
Program Manager,
Data & Modeling Group

PDC 2008 - Los Angeles, CA - Oct. 27-30

dpblogs — Fri, 12 Sep 2008 02:22:00 GMT

Microsoft's premier developer event, the Professional Developer Conference, is almost here. PDC 2008 will feature more than 160 sessions covering a wide range of topics including a number of great sessions from the ADO.NET Team, such as:

Developing Applications Using Data Services

Presenter: Mike Flasko

In the near future, applications will be developed using a combination of custom application code and online building block services, including data-centric services. In this session we discuss advancements in the Microsoft development platform and online service interfaces to enable seamless interaction with data services both on-premises (e.g., ADO.NET Data Services Framework over on-premises SQL Server) and in the cloud (e.g., SQL Server Data Services). Learn how you can leverage existing know-how related to LINQ (Language Integrated Query), data access APIs, data-binding, and more when building applications using online data.

Offline-Enabled Data Services and Desktop Applications

Presenter: Pablo Castro

The ADO.NET Data Services Framework (a.k.a. Project "Astoria") introduced a way of creating and consuming flexible, data-centric REST services. By combining data services with the Microsoft Sync Framework, learn how to create offline-capable applications that have a local replica of their data, how to synchronize that replica with an online data service when a network connection becomes available, and how replicas can be used with the ADO.NET Entity Framework. Also, hear us talk about our plans, see the tools that help client- and server-side setup, and discuss the runtime components and APIs.

Entity Framework Futures

Presenter: Tim Mallalieu

The next version of the Entity Framework adds scenarios in the areas of model driven development, domain driven development, simplicity, and integration. See a preview of production and prototype code for the next version of the Entity Framework as well as a candid discussion with members of the development team.

See you there!!

Elisa Flasko
Program Manager, Data Programmability

Visual Studio 2008 SP1 Beta & .NET 3.5 SP1 Beta

dpblogs — Mon, 12 May 2008 07:59:00 GMT

We are very excited to announce that .NET 3.5 SP1 Beta 1 and Visual Studio 2008 SP1 Beta 1 are now available!

This beta marks the entry of the ADO.NET Entity Framework and ADO.NET Data Services (aka project Astoria) as part of the overall .NET/Visual Studio product install and will be the final beta before the RTM of these two technologies. In addition, this beta will introduce the new date time functions for SQL Server 2008 to LINQ to SQL.

The Entity Framework extends the reach of ADO.NET, providing a new data model that will be the foundation for a range of data services moving forward, and enhances the common ADO.NET provider model enabling a LINQ programming experience against 3^rd party databases. The Entity Framework designer in Visual Studio works with 3^rd party databases as well and enables developers to visualize the data model being used by the application.

ADO.NET Data Services, provides the foundation for building the next generation of data-driven applications and services, building on Windows Communication Foundation (WCF) to provide an end-to-end experience for building data-centric REST based services in .NET. The ADO.NET Data Services framework provides a REST based query model, a means of exchanging metadata (in terms of the Entity Data Model) and client and mid-tier API’s that let people build rich data services and clients in a way that is easier than ever before. You can start with the Entity Framework and expose relational data via the Data Services Framework, you can expose non-relational data using a custom provider, or you can use some of the existing services that already expose these protocols including Live App Storage and Live Spaces Photos.

We invite you all to download this beta and start using these technologies today.

Jason Wilcox

Product Unit Manager, DP Runtime

and

Britt Johnston

Product Unit Manager, DP Tools

Recent ADO.NET Entity Framework provider news - Demos and downloads

dpblogs — Wed, 07 May 2008 08:23:00 GMT

Here are a few quick announcements about ADO.NET providers supporting the Entity Framework. Enjoy!

Core Lab (Connectivity to Multiple Data Stores)

Core Lab was the first ADO.NET provider writer to support Beta 3 of the Entity Framework. Their provider includes connectivity to Oracle, MySQL, PostgreSQL and SQLite databases. For more information, see the announcement on the following pages: http://crlab.com/news/2007/directs430.html and http://crlab.com/news/2008/dcsqlite100.html.

IBM

IBM has released a public beta for their ADO.NET provider that works with Beta 3 of the Entity Framework. For more information, see the announcement on the following page: http://www-128.ibm.com/developerworks/forums/thread.jspa?threadID=203893. IBM also demonstrated their provider in an end-to-end application building scenario using the Entity Framework designer at recent VS Live conference in San Francisco.

MySQL

At the recent MySQL conference in Santa Clara, Reggie Burnett and I co-presented a session talking about MySQL, LINQ and the ADO.NET Entity Framework. As part of the session, we demonstrated using LINQ, Entity SQL and ADO.NET Data Services to access a MySQL database using Beta 3 of the Entity Framework.

Note: Big thanks to Reggie for helping to make this demo work even after injuring his knee. Get well soon.

Npgsql (PostgreSQL connectivity)

Npgsql has released a beta of their PostgreSQL ADO.NET provider that works with Beta 3 of the Entity Framework. You can download the provider at the following page: http://pgfoundry.org/frs/download.php/1730/Npgsql2.0beta3-bin-EntityFrameworkBeta3.zip. For more information on the release, please see the following page: http://pgfoundry.org/forum/forum.php?forum_id=1307.

David Sceppa

ADO.NET Program Manager