Tutorial: Entity Data Source Control

Pregnant Man » Tutorial: Entity Data Source Control

Pregnant Man » Tutorial: Entity Data Source Control — Thu, 19 Jun 2008 03:13:52 GMT

PingBack from http://wordnew.acne-reveiw.info/?p=154

re: Tutorial: Entity Data Source Control

Fatih Sahin — Thu, 19 Jun 2008 11:37:42 GMT

EntityDataSource has a lot of capabilities which makes binding process very easier, without having to write sql join queries. This is really awesome. However, when do you plan to release EF? I am planning to use it in our new project, SP1 Beta has lots of bugs.

re: Tutorial: Entity Data Source Control

Carlos — Thu, 19 Jun 2008 12:09:16 GMT

EntityDataSource seems to be good for smalish applications that don't have tiers (you have the select queries inside the datasource). What would be ~really~ interesting is if the EntityDataSource was used for the multi-tier-story. For me what this should do is:

- The EntityDataSource should track changes on the UI so that it knows when a entity is dirty, new or deleted. This tracking should work for 1-many relationships.

- The EntityDataSource should give you back the entity ready for you to call your service tier, either through wcf or just as normal referenced assembly.

- In your service layer the context should attach the entity and replay all your changes for you.

This would be really nice!

re: Tutorial: Entity Data Source Control

Carlos — Thu, 19 Jun 2008 12:23:45 GMT

Ah also! Another nice feature would be if the EntityDataSource could have multiple views so that you could use the DataMember property on a gridview for example, this means you can bind one to many relationships with one datasource.

EntityDataSource Tutorial on ADO.NET TEam Blog

Hot Topics — Fri, 20 Jun 2008 17:58:54 GMT

A walkthrough on using the new EntityDataSource in ASP.NET websites was added to the ADO.NET Team Blog

re: Tutorial: Entity Data Source Control

Diego Vega — Mon, 23 Jun 2008 06:24:20 GMT

Hello Fatih,

I don’t think we have an official date for the final SP1 release (as you know, the EntityDataSource is going to be included in the first service pack for Visual Studio 2008 and .NET Framework 3.5 together with the Entity Framework), but we will announce it here as soon as we are able to. We don't have plans for any interim release.

Hope this answers your question.

re: Tutorial: Entity Data Source Control

Diego Vega — Mon, 23 Jun 2008 06:46:40 GMT

Hello Carlos,

Thanks for your feedback. The EntiyDataSource was designed to provide a simple out-of-the-box experience to people familiar with other DataSources and with some knowledge of EF and Entity-SQL. Support for multi-tier applications the way you describe wasn’t a goal, but rather to enable direct execution of queries against an EDM model easily and in a mostly declarative manner.

There are certain limitations in the design for the first version that we want to remove in future versions. In the meanwhile, for the scenario you describe, it is very likely that the general-purpose ObjectDataSource executing queries on your own service layer will work much better for you.

Your point about supporting multiple views and DataMember is very interesting. We analyzed the possibility during the development, especially as one way to support master-detail with a single DataSource and in general, covering the requirement to do databinding with EntityCollections. That was really late in the cycle and given that other built-in DataSources do not support it, it represented a high risk, so we decided against it for the first version.

Hope this helps,

Diego

re: Tutorial: Entity Data Source Control

Khaled Hammouda — Tue, 24 Jun 2008 06:24:30 GMT

I have tried to follow the tutorial but bumped into a problem when I tried to build the project after adding the EDM from the database.

In particular, I got the following error in the Error List:

"Error 27 The table 'AdventureWorks2008.Production.Document' was referenced by a relationship, but was not found. C:\dev\projects\EdmWorks\EdmWorks\AdventureWorksModel.edmx 0 1 EdmWorks"

Working backward in the output messages, I found those related messages:

"Message 3 The data type 'hierarchyid' is not supported, the column 'DocumentNode' in table 'AdventureWorks2008.Production.Document' was excluded. C:\dev\projects\EdmWorks\EdmWorks\AdventureWorksModel.edmx 0 1 EdmWorks"

"Message 4 The column 'DocumentNode' on the table/view 'AdventureWorks2008.Production.Document' was excluded, and is a key column. The table/view has been excluded. Please fix the entity in the schema file, and uncomment. C:\dev\projects\EdmWorks\EdmWorks\AdventureWorksModel.edmx 0 1 EdmWorks"

Any suggest on how to fix this would be appreciated.

Khaled

re: Tutorial: Entity Data Source Control

Dinesh — Thu, 26 Jun 2008 04:35:46 GMT

Hi Diego,

I think that for a next release of your EntityDataSource you should really look into supporting enterprise level solutions, as the entity framework is targeted for bigger applications than to linq to sql. In any realistic enterprise application, there is a real need to separate presentation from business logic and data concerns which necessitates the need for a tiered approach. With a tiered approach, the EntityDataSource is virtually unusable.

Secondly, even if we go with the ObjectDataSource, it does not support change tracking for entities requiring a manual replay process on the service tier. This is cumbersome, error-prone and definitely something that can be 'framework'ed.

Any thoughts?

Regards,

Dinesh

re: Tutorial: Entity Data Source Control

Roy — Tue, 09 Dec 2008 17:54:17 GMT

I am using ADO.NET Entity Data Model template to generate edmx code in Visual Studio 2008. I have selected more than a hundred objects in my database. However, some of the objects are missing in the generated code. Is there a limitation on how many object could be selected? If yes, what is the work around?

re: Tutorial: Entity Data Source Control

Todd Mera — Wed, 25 Mar 2009 03:11:30 GMT

Thanks for the demo. Very helpful.

I think there is a small error on step 4...

----------------------------------

<asp:ControlParameter ControlID="ddCategories"

Type="Int32"Name="ProductCategoryID" />

</WhereParameters>

----------------------------------

ControlID="ddCategories"

--- Should be ---

ControlID="ddCategory"

re: Tutorial: Entity Data Source Control

David McCarter — Mon, 16 Nov 2009 20:26:28 GMT

I like this article. But what do I do when the a null comes back in the Where statement? I'm getting a java script error.

David