Laravel - Getting Started - Chunking Results

Your application may run out of memory if you attempt to load tens of thousands of Eloquent records via the all or get methods. Instead of using these methods, the chunk method may be used to process large numbers of models more efficiently.

The chunk method will retrieve a subset of Eloquent models, passing them to a closure for processing. Since only the current chunk of Eloquent models is retrieved at a time, the chunk method will provide significantly reduced memory usage when working with a large number of models:

    
    use App\Models\Flight;
    
    Flight::chunk(200, function ($flights) {
        foreach ($flights as $flight) {
            //
        }
    });
	

The first argument passed to the chunk method is the number of records you wish to receive per "chunk". The closure passed as the second argument will be invoked for each chunk that is retrieved from the database. A database query will be executed to retrieve each chunk of records passed to the closure.

If you are filtering the results of the chunk method based on a column that you will also be updating while iterating over the results, you should use the chunkById method. Using the chunk method in these scenarios could lead to unexpected and inconsistent results. Internally, the chunkById method will always retrieve models with an id column greater than the last model in the previous chunk:

    
    Flight::where('departed', true)
        ->chunkById(200, function ($flights) {
            $flights->each->update(['departed' => false]);
        }, $column = 'id');