Laravel check for constraint violation

Question

I was curious if there is a way we can check if there is a constraint violation error when delete or insert a record into the database.

The exception thrown is called \'

Answer 1

If you are using Laravel version 5 and want global exception handling of specific cases you should put your code in the report method of the /app/Exception/Handler.php file. Here is an example of how we do it in one of our micro services:

public function render($request, Exception $e)
{
    $response   = app()->make(\App\Support\Response::class);
    $details = $this->details($e);

    $shouldRenderHttp = $details['statusCode'] >= 500 && config('app.env') !== 'production';
    if($shouldRenderHttp) {
        return parent::render($request, $e);
    }

    return $response->setStatusCode($details['statusCode'])->withMessage($details['message']);
}

protected function details(Exception $e) : array
{
    // We will give Error 500 if we cannot detect the error from the exception
    $statusCode = 500;
    $message = $e->getMessage();

    if (method_exists($e, 'getStatusCode')) { // Not all Exceptions have a http status code
        $statusCode = $e->getStatusCode();
    } 

    if($e instanceof ModelNotFoundException) {
        $statusCode = 404;
    }
    else if($e instanceof QueryException) {
        $statusCode = 406;
        $integrityConstraintViolation = 1451;
        if ($e->errorInfo[1] == $integrityConstraintViolation) {
            $message = "Cannot proceed with query, it is referenced by other records in the database.";
            \Log::info($e->errorInfo[2]);
        }
        else {
            $message = 'Could not execute query: ' . $e->errorInfo[2];
            \Log::error($message);
        }
    }
    elseif ($e instanceof NotFoundHttpException) {
        $message = "Url does not exist.";
    }

    return compact('statusCode', 'message');
}

The Response class we use is a simple wrapper of Symfony\Component\HttpFoundation\Response as HttpResponse which returns HTTP responses in a way that better suits us.

Have a look at the documentation, it is straightforward.