Why $stmt->fetch(PDO::FETCH_NUM); is returning arrays with numeric indices ans columns name?

Question

Trying to get array from database rows with numeric indices only with:

$sql = "SELECT * from resumenes";
    $stmt = $db->prepare($sql);
    $stmt->execute();
    $stmt->fetch(PDO::FETCH_NUM);
    foreach ($stmt as $row) {
        print_r($row);
    }

I'm getting both, numeric indices and associative indices as if he had used PDO::FETCH_BOTH

Answer 1

3 possibilities :

1. Use $row returned by $stmt->fetch(PDO::FETCH_NUM) in a loot

$stmt = $db->prepare($sql);
$stmt->execute();
while ($row = $stmt->fetch(PDO::FETCH_NUM)) {
    print_r($row);
}

2. Specify request fetch mode :

$stmt = $db->prepare($sql);
$stmt->setFetchMode(PDO::FETCH_NUM); // Fetch mode for this statement
$stmt->execute();
foreach ($stmt as $row) {
    print_r($row);
}

3. Specify default fetch mode, tipically after connection :

$pdo = new PDO(...);
$pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_NUM);