error handling advice

Hello,

My application is near completion and currently being beta tested at my work place by others. While on my development system everything seems stable, in the wild it's shown to be less stable than I thought.

Hence I'm wanting to write some robust error handling into the application. Right now the largest instances of errors happen when doing an 'insert' or 'update'.

So far I've managed to loose server connections on a few occasions through unmanaged insert / update errors, resulting in server restarst to fix.

I've added code below and I an wondering whether I'm on the right track, or if there is a better way to handle insert, update errors.

Any advice appreciated..

@{
    var userErrMsg = "";
    var errMsg = "";
    var actiontype = Request["action-type"];
    var projectno = Request["projectno"];
    var description = Request["Description"];
    var db = Database.Open(App.conDatabase);
        
        try {
            var row = processSQL.getUsername(App.conDatabase, WebSecurity.CurrentUserName);

            if(actiontype == "new")
            {
                var author = row.Username;
                var createddate = DateTime.Now;
              
                var sql = "INSERT INTO tblProjectBenefits (Description, ProjectRef, Author , CreatedDate) VALUES (@0, @1, @2, @3)";
                db.Execute(sql, description, projectno ,author, createddate);
            }
    
        //edit user post
            else if(actiontype == "edit")
            {
               var id = Request["ID"];

               var updateby = row.Username;
               var updatedate = DateTime.Now;
     
               var sql = "UPDATE tblProjectBenefits SET Description = @0, ProjectRef = @1, UpdateBy = @2, UpdateDate = @3 WHERE ID = @4";
               db.Execute(sql, description, projectno, updateby, updatedate, id);
            }
            else if(actiontype == "delete")
            {
               var id = Request["ID"];
               var sql = "DELETE FROM tblProjectBenefits WHERE ID=@0";
               db.Execute(sql, id);
            }
        }
        catch (Exception ex) {
            // You can use the exception object for debugging, logging, etc.
            errMsg = ex.Message;
            // Create a friendly error message for users.
            userErrMsg = "An exception has occured, please contact "
                + "your system administrator.";
        }
        finally
        {
                //Any cleanup code
                db.Close();
        }
    
}

Re: error handling advice

If I do not know what is the error, I would not catch.

Re: error handling advice

Okay, be specific about what errors I want to catch..

Should I also be closing the db connection everytime I make a call?

does the finally { } run on every connection even if there is no failure?

Re: error handling advice

For the exception you should know what exception may cause, then right like this.

catch (InvalidCastException e) //http://msdn.microsoft.com/en-us/library/0yd65esw(v=vs.80).aspx
{
}

And for finally{ } it will run in any situation, so put db.close in finally is right.