How handle UpdateException?

Question

I need handle exception duplicate.

var resource = new Resource() { url = tbUrl.Text };
try
{
    context.Resource.AddObject(resource);
    context.SaveChanges();
}   
catch(UpdateException ex)
{
    // how to know exactly which is why the error occurred
}
catch (Exception ex)
{

    throw;
}

UPDATE:

I need to catch an error that occurs when I try to not add unique value. UpdateException - is triggered when an error in adding data.

Do you mean you want to find out whether `resource` is already added to `context.Resource`? Otherwise, I don't understand your question. — Sebastian Mach, Jul 12 '11 at 14:22

Jules Bartow · Accepted Answer · 2012-05-30T11:35:03.667

This may be a little late, but for anyone with an ASP.NET database update error looking for details, the InnerException error handler is extraordinary helpful and detailed.

        try { 

            db.SaveChanges();                              
        }

        catch (System.Data.UpdateException ex)    
        {
            Console.WriteLine(ex.InnerException);
        }


        catch (System.Data.Entity.Infrastructure.DbUpdateException ex) //DbContext
        {
            Console.WriteLine(ex.InnerException);
        }

        catch (Exception ex)
        {

            Console.WriteLine(ex.InnerException);
            throw;
        }

The T-SQL in the database prevents the insertion of duplicate cities.

USE [ModelFirstApplication]
GO

/****** Object:  Index [UQ_Address_City]    Script Date: 5/30/2012 7:26:16 AM ******/
ALTER TABLE [dbo].[Addresses] ADD  CONSTRAINT [UQ_Address_City] UNIQUE NONCLUSTERED 
([City] ASC)
GO

So, if the user tries inserting "Spokane" a second time into the Addresses table into this demo application, the above exception handler reports

System.Data.UpdateException: An error occurred while updating the entries. 

See the inner exception for details. ---> 

System.Data.SqlClient.SqlException: Violation of UNIQUE KEY constraint 'UQ_Address_City'. 
Cannot insert duplicate key in object 'dbo.Addresses'. 
The duplicate key value is (Spokane).
The statement has been terminated.

Knowing which exception handler to use is pretty darned handy and your question is quite clear.

score 0 · Answer 2 · answered Jul 12 '11 at 14:25

0

See AppDomain.CurrentDomain.UnhandledException. Also, for WPF application is make sense to look at the Application.Current.DispatcherUnhandledException

answered Jul 12 '11 at 14:25

sll

61,540
22
104
156

score -1 · Answer 3 · answered Jul 12 '11 at 14:24

-1

the best practice is to write the exception message and stack trace to log file and get the data by reading the log file i reccomand using log4net http://sadi02.wordpress.com/2008/06/29/log4net-tutorial-in-c-net-how-can-i-show-log-in-a-file/

answered Jul 12 '11 at 14:24

kleinohad

5,800
2
26
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How handle UpdateException?

3 Answers3