README

Iterate through large database results with easy

Usage for ORM

Create query builder as usual. Dont forget about orderBy and maxResults.

$testEntityRepository = $this->entityManager->getRepository(TestEntity::class);
$qb = $testEntityRepository->createQueryBuilder('t')
    ->orderBy('t.id', 'ASC')
    ->setMaxResults(100)
;

$cursorIterator = new DoctrineORMCursorPaginator($qb);

foreach ($cursorIterator as $testEntity) {
    //...
}

DoctrineORMCursorPaginator will hold only 100 records in memory to prevent memory leaks and efficiently iterate through even large datasets.

First sql:

SELECT ... FROM table ORDER BY id ASC LIMIT 100

Next:

SELECT ... FROM table WHERE id > {$id_from_last_record} ORDER BY id ASC LIMIT 100

You can also specify more order by fields

$testEntityRepository = $this->entityManager->getRepository(TestEntity::class);
$qb = $testEntityRepository->createQueryBuilder('t')
    ->select('t.id', 't.createdAt')
    ->orderBy('t.createdAt', 'DESC')
    ->addOrderBy('t.id', 'DESC')
    ->setMaxResults(100)
;

$cursorIterator = new DoctrineCursorIterator($qb);

foreach ($cursorIterator as $testEntity) {
    //...
}

You can change hydration mode

$cursorIterator = new DoctrineCursorIterator($qb, AbstractQuery::HYDRATE_ARRAY);

And even set query hints

$cursorIterator = new DoctrineCursorIterator(
    qb: $qb,
    queryHints: [
        'fetchMode' => [
            TestEntity::class => [
                'field' => ClassMetadataInfo::FETCH_EAGER
            ]
        ]
    ]
);

You wanna batch? Lets batch:

$cursorPaginator = new DoctrineORMCursorPaginator($qb);

foreach ($cursorPaginator->batch() as $entities) {
    foreach ($entities as $testEntity) {
        $cnt++;
    }
}

By default batch size equals to maxResults but you can also specify desired amount by yourself:

$my_batch_size = 1000;

$cursorPaginator = new DoctrineORMCursorPaginator($qb);

foreach ($cursorPaginator->batch($my_batch_size) as $entities) {
}

Usage for DBAL

Just use DoctrineDBALCursorPaginator instead.

$queryBuilder = $this->connection->createQueryBuilder();

$queryBuilder
    ->select('id', 'name')
    ->from('test')
    ->orderBy('id', 'ASC')
    ->setMaxResults(100)
;

$cursorPaginator = new DoctrineDBALCursorPaginator($queryBuilder);

$cnt = 0;
foreach ($cursorPaginator as $row) {
    $cnt++;
}