PHP MySQLi A failed prepared query will kill all future code/queries in the script

Question

I'm trying to figure out exactly how I should work around this. When I have one MySQLi query fail, it automatically kills the rest of the script. For instance

//Pure example code
$data = $mysqli->prepare("somequery");
$data->execute(); // Execute the prepared query.
//If the query above fails, the rest of the script doesn't get executed.

Basically, I'm trying to figure out how I can stop PHP from killing the script when the query fails. Any ideas? I moved to prepared statements because of the supposed performance and security gains. It'd be a pain to rewrite everything to plan old queries.

Thanks,

Answer 1

You need to actually check for success, rather than blindly executing $data->execute() when data may be false, which will raise an error and abort your script.

From the docs, prepare...

returns a statement object or FALSE if an error occurred.

Answer 2

PHP kills scripts on fatal errors. If this line fails:

$data = $mysqli->prepare("somequery");

PHP will not kill your script but $data is set to false. The script will be killed upon the next line:

$data->execute();

With the following error:

Fatal error: Call to a member function execute() on a non-object in...

First of all, you need to enable error_reporting so that you could be able to diagnose the problem (and perhaps figure out the solution) yourself. Secondly, as @meagar mentioned, check for return values of mysqli functions:

$data = $mysqli->prepare("somequery");
if($data === false) {
    echo $mysqli->error;
    // dying isn't the most graceful approach by the way
    die();
}
if($data->execute() === false) {
    echo $mysqli->error;
    die();
}

Changing from mysql_* to mysqli has nothing to do with your issue. If you were using mysql_* you still need to check the return values from functions. A generic rule: never assume that your queries will always succeed.

Answer 3

if($data = $mysqli->prepare("somequery")) {
// binding
  $data->execute(); // Execute the prepared query.
}

From the documentation