Hi Bonnie,

First, thank you for your message.

I will have to review again your blog entries; it has been a while. What I was thinking (since I posted this message) is that I need to modify the method ExecuteCommand() of DAL to return True or False. And if False, set the error message to the property .ErrorMessage of DAL object. That way, UI can get the error message from the DAL object and deal with it. Therefore, I will need to change the code that Throws the error and rather just get the error message and return False. At least, this is how I do it in my VFP app. But maybe this is not the way things are done in .NET. I will, of course, re-read your blog and your suggestion in this message.

But I was thinking also that I need to learn how to deal with this "Throw" syntax. Would the code in UI have to catch the error that DAL Throws?

>Hi Dmitry,
>
>Thanks for referring to me as "famous". <g>
>
>So, if you used my example totally as your DAL, then you probably had to tweak it a bit (for lurkers, I believe Dmitry is referring to Part III of my DataAccess series: http://geek-goddess-bonnie.blogspot.com/2009/10/dataaccess-part-iii.html).
>
>I noticed in the Start() method that it handles exceptions by this statement:
>

this.AddToErrorMessage(e);

>And of course there is no AddToErrorMessage() method in my example. There is, however, an ErrorMessage property in the original BBDataAccess class shown in Part II: http://geek-goddess-bonnie.blogspot.com/2009/10/dataaccess-part-ii.html
>
>If your Start() method returns a false, you should be able to access the ErrorMessage property and do something with it, like return it to your UI.
>
>Does this help?
>
>~~Bonnie
>
>
>>Hi,
>>
>>How do you deal with cases when database update (SQL Server) fails (e.g. constraints)? Here is a code from the DAL class that updates the database (this is not my code; I borrowed it from a blog of a famous person here <g>):
>>
>>

>>       protected void SaveTable(DataTable Table, string SaveProc)    
>>        {        
>>            foreach (DataRow row in Table.Rows)
>>            {            
>>                this.SetAllParameters(row);
>>                this.ExecuteCommand(SaveProc);
>>            }    
>>        }
>>
>>// The problem occurs in method ExecuteCommand.  And the ExecuteCommand method looks like this:
>>//  simplified
>>protected void ExecuteCommand(string StoredProcName)    
>>        {        
>>
>>            try         
>>            {             
>>                this.oCommand.ExecuteNonQuery();
>>            }        
>>            catch (Exception ex)
>>            {
>>                // !! This is where I get the error that Breaks the code.  
>>                throw ex;
>>            }        
>>         }
>>
>>

>>
>>What I would like is to be able to return the error message back to the UI layer to be displayed.
>>
>>TIA for any suggestions.