hello

i use

try

catch

end try

====================

in try section there are more than one excepetced error

in the catch section an action sould be done depending on the error type

how could i determine what error happens there?

Regards 

ghassan_aljabiri:

how could i determine what error happens there?

You can catch specific exceptions in your Catch block as shown below. And as always common exception is handled as the last one.

Catch(Exception ex)
{
          if (ex is System.Security.SecurityException)   
{   
        //Take action as you wish   
    }   
else  if
   (ex is System.Data.SqlException)
{
    //Take the action
}

}

you can do it using following approach. The benefit of this approach is that when exception will occur, it will be catched by its corresponding catch block. This approach is faster and most recommended.

try        

        {

            // some code here

        }

        catch (SqlException sqlex)

        {

            // do something here

        }

        catch (FieldAccessException fexp)

        {

            // do something here

        }

        catch (Exception ex)

        {

            // do something here

        }

Hope it will help.

yes that is greate start , but what if i want it with more specification

i mean , an sqlexception may happen because a dublicatied primary key , table not found , connection error , i need to handle every one in a special way

in VB 6 i used to use err.number

where every error has its code

is there a similer thing in vb.net (asp.net) 

Yes we have the Err.Number in vb.net as well.

Please view the following link for details.

http://msdn.microsoft.com/en-us/library/5hsw66as.aspx

Dont relay your code with exception.

Exception is very expensive in Asp..net application.

It is not a good practice. Try to handel  your application process with programming logic.

ghassan_aljabiri:

A sql exception may happen because a duplicated primary key, table not found, connection error.  I need to handle every one in a special way

Some of these errors should not happen. For example:

• Primary keys should be identity integers. As they are system derived, duplication is not possible.
• Table not found - are you using dynamic TSQL to generate table names?
• Connection error - if a class fails to connect to the database, it should throw an InvalidOperationException with a message citing the connection string used.

I suggest you get a copy of the Framework Design Guidelines from http://www.amazon.com/exec/obidos/tg/detail/-/0321246756/qid=1126565222/sr=8-1/ref=pd_bbs_1/102-0703728-8921753?v=glance&s=books&n=507846 and study chapter 7.

The second edition is available from:

http://www.amazon.com/Framework-Design-Guidelines-Conventions-Libraries/dp/0321545613/ref=dp_ob_title_bk/190-4796535-3943148

hello

TATWORTH:

Primary keys should be identity integers. As they are system derived, duplication is not possible.

if inserted data is taken automatically from another database that apply no restrections on the id field and u want to use the same feild as a primary key in the new database , and u want to discard the duplicated ids , you need a way to catch a dublicated primary key

TATWORTH:

Table not found - are you using dynamic TSQL to generate table names?

 if the database is created by you , but tables is being created by a script (a user should run it) so you may expect a user to try to insert data before creating his tables , I know there are too many ways to prevent this with code , but I choosed this method!

TATWORTH:

Connection error - if a class fails to connect to the database, it should throw an InvalidOperationException with a message citing the connection string used.

this one was helpfull , thanks alot

TATWORTH:

I suggest you get a copy of the Framework Design Guidelines from http://www.amazon.com/exec/obidos/tg/detail/-/0321246756/qid=1126565222/sr=8-1/ref=pd_bbs_1/102-0703728-8921753?v=glance&s=books&n=507846 and study chapter 7.

The second edition is available from:

http://www.amazon.com/Framework-Design-Guidelines-Conventions-Libraries/dp/0321545613/ref=dp_ob_title_bk/190-4796535-3943148

 this one was very helpfull , thanks alot

:|