PDO中的mysql_result

Question

Below is the code I have, it was all written in mysql. I am trying to switch to PDO. My question is, what is the equivalent of mysql_result in PDO?

$query = "SELECT id, firstname, lastname FROM table";
if($mysql_query = mysql_query($query)){
    $id = mysql_result($mysql_query, 0, 'id');
    $firstname = mysql_result($mysql_query, 0, 'firstname');
    $lastname = mysql_result($mysql_query, 0, 'lastname');
}

So far, I am only able to execute the $query by doing the following below.

$query = $PDO -> prepare("SELECT id, firstname, lastname FROM table");
$query -> execute();

Answer 1

Try this...

$query = $PDO->prepare("SELECT id, firstname, lastname FROM table");
$query->execute();
$res = $query->fetchAll(PDO::FETCH_ASSOC);
var_dump($res);

==== update in response to comment ====

$query = $PDO->prepare("SELECT id, firstname, lastname FROM table");
$query->execute();
$people = $query->fetchAll(PDO::FETCH_CLASS, 'stdClass');
foreach($people as $person) {
    echo 'ID: ' . $person->id . PHP_EOL .
         'First Name: ' . $person->firstname . PHP_EOL .
         'Last Name: ' . $person->lastname . PHP_EOL;
} 

Answer 2

As Ian stated above is one way, or if your not utilizing the prepare function then you could just do:

$sth = $PDO->query("SELECT id, firstname, lastname FROM table");

if ($sth->rowCount() > 1) {
    // One way to get the results if you have more then one row
    foreach ($sth as $row) {
        echo "ID: ".$row['id']."\n";
        echo "First name: ".$row['firstname']."\n";
        echo "Last name: ".$row['lastname']."\n";
    }
} elseif ($sth->rowCount() == 1) {
    // Or this way if you just have one row
    $result = $sth->fetch(PDO::FETCH_ASSOC);

    echo "ID: ".$result['id']."\n";
    echo "First name: ".$result['firstname']."\n";
    echo "Last name: ".$result['lastname']."\n";
}