Using the Entity Framework and the ObjectDataSource Control, Part 1: Getting Startedhttp://asp.netTue, 20 Nov 2012 16:39:01 GMTumbracoComments for Using the Entity Framework and the ObjectDataSource Control, Part 1: Getting StartedenComment Posted by kouwenhttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedMon, 09 May 2011 15:43:59 GMT00000000-0000-0000-0000000013114We have been having this discussion today. Some people say EF combines the BLL and DAL thus no point of developing them separately(Double code maybe). I'm getting more puzzled. Any suggestions ?

]]>Comment Posted by tdykstrahttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedTue, 10 May 2011 17:29:40 GMT00000000-0000-0000-0000000013125The Entity Framework provides a framework for data access -- it doesn't have any business logic and so it can't in itself combine the business logic and data access layers. It would be more accurate to think of it as a key part of the data access layer. Not everyone means the same thing by BLL and DAL, however, or draw the boundary lines between them in the same way. You could certainly combine your BLL and DAL, and the Entity Framework could be a part of that combination.

]]>Comment Posted by KaNangahttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedWed, 06 Jul 2011 07:28:28 GMT00000000-0000-0000-0000000013703Thanks for the tutorial... great learning tool!

]]>Comment Posted by haos11http://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedFri, 26 Aug 2011 18:18:51 GMT00000000-0000-0000-0000000014060In Repository class you didn't implement destructor (~SchoolRepository), so I think that GC.SuppressFinalize and 'bool disposing' are unnecessary.

]]>Comment Posted by antonioplaishttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedFri, 18 Nov 2011 06:41:21 GMT00000000-0000-0000-0000000014653I'm trying to reproduce this tutorial and when I bind the gridview to the repository class (ienumerable) I receive an error message stating that the datasource should implement iQueryableDatasource.

What's the trick? (using VWD 2010 SP1 on Windows 7 Ultimate SP1)

]]>Comment Posted by antonioplaishttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedFri, 18 Nov 2011 07:08:40 GMT00000000-0000-0000-0000000014654Sorry, I got my mistake! I had a QueryExtender attached to the Datasource and that caused the error. Everything working fine now!

BTW, congratulations for the fantastic tutorial.

]]>Comment Posted by tayhohttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedTue, 28 Feb 2012 00:01:53 GMT00000000-0000-0000-0000000014959Thanks for this helpful tutorial. We had a problem with entering a start date

in the Australian date format (i.e. dd/MM/yyyy) in the DeparmentsAdd.aspx page

and the Departments.aspx page.

The error message is: "Cannot convert value of parameter 'StartDate' from

'System.String' to 'System.Date' ". I searched on the internet but could not find

a solution for this. Any ideas? Thank you again.

]]>Comment Posted by tdykstrahttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedFri, 09 Mar 2012 14:56:16 GMT00000000-0000-0000-0000000015078@tayho - I recommend trying the ASP.NET forum or StackOverflow. If you decide to try StackOverflow, I'd appreciate hearing what the answer is so I can incorporate it into the next release of the tutorial (if you use the forum, I'll get the thread automatically).

]]>Comment Posted by Mugnaiohttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedTue, 26 Jun 2012 10:03:59 GMT00000000-0000-0000-0000000015853When I try to Edit and Update i get an error about decilmal format on Budget: my currency is euro, decimal format is with the ",". If I Update for example Mathematics with no modification i get an exception: Exception: 250000,0000 is not a valid value for Decimal. If i try to subst the "," with the "." I get no exception but "The field Budget must be a valid decimal." from the validation control.

]]>Comment Posted by tdykstrahttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedThu, 28 Jun 2012 19:39:38 GMT00000000-0000-0000-0000000015877@Mugnaio - Have you downloaded the completed project and tried that? If it works for you, you can compare that with what you created by following the tutorial to see what's different. The error with a comma is expected, but replacing the "," with a "." works in the downloaded project.

]]>Comment Posted by cpzuphttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedTue, 25 Sep 2012 11:30:51 GMT00000000-0000-0000-0000000016508I have a question on edit/delete. I am using a similar structure with different names. I have two entities named "UncertaintyFamily" and "Classification". Assume that the entity keys and relationships are correct. All code is identical to this example except the names of my entities and attributes are different. I am using Bind("") and bound fields instead of Eval("") and dynamic fields.

Insert and Select both work perfectly.

When I try to edit a row, it gives me an error in the repository:

m_Context.Attach(originalFamily); -- "an object with a null entitykey value cannot be attached to an object contex".

*When hovering over the new and original parameters in the Update method in the repository, all fields, including the ID field, are populated and correct.

*The EntityKey is set to True in the model for both the parent and child entities.

*The DataKeyNames for the grid is set to the ID of the UncertaintyFamily table.

*I am using a label to bind the Classification.Abbreviation while viewing and a dropbox like in the example to edit.

*Delete stopped working when I added the ConflictDetection parameter in the ODS saying it could not find a property named "Classification.Abbreviation" on the type specified by the DataObjectTypeName property in ObjectDataSource "odsUncertaintyFamilies" (which is populating the grid).

Can someone please help? Thanks.

]]>Comment Posted by cpzuphttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedTue, 25 Sep 2012 12:03:11 GMT00000000-0000-0000-0000000016509Ah, got it.

*I changed Bind("") to Eval("") in the label control and that fixed Delete().

*I changed m_Context.Attach(originalFamily) to m_Context.UncertaintyFamilies.Attach(originalFamily) in the update method and update works.

]]>Comment Posted by mhaltamimihttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedThu, 11 Oct 2012 07:46:11 GMT00000000-0000-0000-0000000016603thank you for this great tutorial

you know... i prefer to do the following in DepartmentsDetailsView_ItemInserting in order to get the Instructor Id, its just one step oen more easy :D

DropDownList InstructorsDropDownList = DepartmentsDetailsView.Rows[0].FindControl("InstructorsDropDownList") as DropDownList;

]]>Comment Posted by thomastwosomehttp://asp.net/web-forms/tutorials/continuing-with-ef/using-the-entity-framework-and-the-objectdatasource-control,-part-1-getting-startedTue, 20 Nov 2012 16:39:01 GMT00000000-0000-0000-0000000016840I would love to see a VB version of this tutorial! Also a printable PDF (like many of the other tutorials on this site have) would be helpful.

Wonderful, helpful learning tool. Thank you for the time you took to create these tutorials!

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