Question

I have an application built in Delphi and it accesses MySQL database using MyDAC componentsand Windows XP O.S. .

I want this application to run on System Startup,so I added the Application shortcut to the Startup folder also added a Registry key .

But when I start my system ,first an Microsoft error message pops up

 Myapplication.exe has encountered a problem and needs to close.

and asks for error reporting.
After this another error from the application comes up

 Exception EMyError in module MyApplication.exe
 Can't connect to MySQL server on 'localhost'(10061)
 Socket error on connect.

how do I overcome this?

any help appreciated

Answer 1

Some hints:

• You should better implements a Windows Service so that the application will start even before the first user log into the system;
• Services may be started before the network or the DB is ready, so you get this EMyError exception – in this case, use Sleep(5000) to wait for 5 seconds, then retry until the connection will take place.

A typical code, using a service, may be:

procedure TMyService.Execute;
var retry: boolean;
begin
  retry := true;
  repeat
    try
      ConnectToDatabase;
      retry := false; // connection success
    except
      on E: EMyError do 
        sleep(5000); // wait 5 seconds and retry
    end;
    if Terminated then
      exit; // avoid endless loop
  until not retry;
  // ... now you are connected and you can continue