Symfony2 / Doctrine make $statement->execute() not “buffer” all values

Question

I\'ve got a basic codeset like this (inside a controller):

$sql = \'select * from someLargeTable limit 1000\';
$em = $this->getDoctrine()->getManager();
$c         


        

Answer 1

The selected answer is wrong and @kroky's answer should be selected as the correct one.

The problem is Buffer vs Unbuffered Queries.

Now it won't be a good idea to change the behaviour for all queries, because:

Unless the full result set was fetched from the server no further queries can be sent over the same connection.

Hence, it should only be used when necessary. Here is a full working example with >200k objects:

    $qb = ...->createQueryBuilder('p');

    $this
        ->em
        ->getConnection()
        ->getWrappedConnection()
        ->setAttribute(\PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);

    $query = $qb->getQuery();
    $result = $query->iterate();
    $batchSize = 20;
    $i = 0;
    foreach ($result as $product)
    {
        $i++;

        var_dump($product[0]->getSku());

        if (($i % $batchSize) === 0) {
            $this->em->flush();
            $this->em->clear(); // Detaches all objects from Doctrine!
        }
    }

It most likely needs some refinement.