How to fetch results one by one in Doctrine 1.2? - php

Question

How can I make something similar to classic PHP PDO
while ($obj = $stmt->fetch()) {...}
in Doctrine 1.2.
I've tried
while ($obj = $query->fetchOne()) {...}
but it returns always only the first object found.
Is there any way I could implement this behaviour?
Doesn't really matter my query. It's a plain simple one (note that I am in the *Table class of the model)
$query = $this->createQuery('a');

Answer 1

While working on a migration command in symfony2 I discovered that $query->executes(); fetches the complete result set into RAM before returning it.
This is not a problem with a small amount of data, but with bigger results your process might run OutOfMemory.
To solve the problem you can iterate through the results "one by one" with this statement:
$query->iterate();
I thing its similare to this PDO statement: while ($obj = $stmt->fetch()) {...}
A more complete example might look like this:
$em = $this->getContainer()->get('doctrine');
$iterator = $em->getRepository('AcmeBundle:Entity')
->createQueryBuilder('e')
->getQuery()->iterate();
foreach($iterator as $item){
$item = $item[0];
// Your logic here:
$item->getId();
....
}
Found this in the doctrine documentation.

Answer 2

Have you tried:
while ($obj = $query->execute()) {...}
And if you want to fetch an array instead of objects:
while ($obj = $query->execute(array(), Doctrine_Core::HYDRATE_ARRAY)) {...}

Answer 3

If you got the connection, do it like this:
$stmt = $conn->query($queryString);
while ($obj = $stmt->fetch()) {...}
With fetchOne() you will only get one entry at all.

Answer 4

Use the hydrate mode Doctrine_Core::HYDRATE_ON_DEMAND
$q = Doctrine_Query::create()
->select('...')
->from('...');
// Returns instance of Doctrine_Collection_OnDemand
$result = $q->execute(array(), Doctrine_Core::HYDRATE_ON_DEMAND);
foreach ($result as $obj)
{
// do something with your object
}
More information : Data Hydrators — Doctrine 1.2.4 documentation