Aggregating

The Basics

Make an index and add a few documents to it:

use Ehann\RediSearch\Index;

$bookIndex = new Index($redis);

$bookIndex->add([
    'title' => 'How to be awesome',
    'price' => 9.99
]);

$bookIndex->add([
    'title' => 'Aggregating is awesome',
    'price' => 19.99
]);

Now group by title and get the average price:

$results = $bookIndex->makeAggregateBuilder()
    ->groupBy('title')
    ->avg('price');

Cursor-Based Pagination

For large result sets, use withCursor() to retrieve results in batches instead of all at once. The first call returns an initial batch; subsequent batches are read with cursorRead(). Always call cursorDelete() when done to free the server-side cursor.

$builder = $bookIndex->makeAggregateBuilder();

// Request the first batch of up to 50 results.
$result = $builder
    ->groupBy('author')
    ->count()
    ->withCursor(50)
    ->search();

// $result contains the first batch and a cursor ID.
$cursorId = $result->getCursorId();

// Read subsequent batches until the cursor is exhausted (cursorId becomes 0).
while ($cursorId !== 0) {
    $next = $builder->cursorRead($cursorId, 50);
    $cursorId = $next->getCursorId();
    // process $next->getDocuments() ...
}

// If you need to abandon iteration early, delete the cursor explicitly.
$builder->cursorDelete($cursorId);