php - Iterating over generators with while

I'm writing a PDO wrapper for a new project. A very common pattern with SQL is to write a statement such as

while ($row = $connection->fetch($sql)) {
    ...
}
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My wrapper function is essentially this:

public function fetch($query, $bindings)
{
    $stmt = $this->getPdo()->prepare($query);

    $stmt->execute($bindings);

    $stmt->setFetchMode($this->getFetchMode());

    foreach ($stmt as $record) {
        yield $record;
    }
}
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But I can't use the values if I call this using awhile loop as above. Doing avar_dump says that$row is a Generator object. If I use aforeach, avar_dump shows the database data, as expected. Is it simply not possible to traverse over generators usingwhile, or have I confused myself here somewhere?