How can I handle this kind of exceptions (in Doctrine)

Question

Can you tell me how can I handle this kind of exceptions:

Fatal error: Uncaught exception 'Doctrine_Connection_Exception' with message 'PDO Connection Error: SQLSTATE[HY000] [2013] Lost connection to MySQL server at 'reading initial communication packet', system error: 110' in ...

It happens when connection with MySQL is lost during query. I need to handle this exception so I can show 500 error page so the crawlers do not cache page, and to redirect user to appropriate "Try again" page.

PS I have a lot's of code, so I can not go trough all code to put try/catch block. I need something simple and yet effective.

Answer 1

I need something simple and yet effective

try/catch will be your only choice IMO. If you have to many places where you need to add a try/catch clause, you could move this particulat piece of code into a seperate function.

If, say, this line throws the execption

$con->query($your_DQL_query) //something happends here with the results

move it to an something like

function goodQuery($sql) {
  try {
    $con->query($sql);
  } catch (Doctrine_Connection_Exception $dce) {
    //do something
  }
}

You still need to replace all of your "throwing" methods with a call to function goodQuery(...) but this will make future development easier since the exception is handled in one place.

Answer 2

You don't handle it with Doctrine... You handle with your coding language. If you're using PHP:

try {
  SomeClass::do_something(parameter);
} catch(DoctrineException $e) {
  show_error($e->getMessage());
}

This is obviously sudo-code, but it gives you an idea... You could show a general error or be specific and display doctrine's message...