How can fetching huge records using Laravel and MySQL?

问题

I Need experts Suggestions and Solutions. We are developing job portal website here by handle around 1 million records. We are facing records fetching timeout errors. How can I handle those records using laravel and MySql?

We are trying to follow steps:

1. Increase the PHP execution time
2. MySql Indexing
3. Paginations

回答1:

You should be chunking results when working with large data sets. This allows you to process smaller loads, reduces memory consumption and allows you to return data to the User while the rest is being fetched/processing. See the laravel documentation on chunking:

https://laravel.com/docs/5.5/eloquent#chunking-results

To further speed things up you can leverage multithreading and spawn concurrent processes that each handle a chunk at a time. Symfony's Symfony\Component\Process\Process class makes this easy to do.

https://symfony.com/doc/current/components/process.html

回答2:

From the docs:

If you need to work with thousands of database records, consider using the chunk method. This method retrieves a small chunk of the results at a time and feeds each chunk into a Closure for processing. This method is very useful for writing Artisan commands that process thousands of records. For example, let's work with the entire users table in chunks of 100 records at a time:

DB::table('users')->orderBy('id')->chunk(100, function ($users) {
    foreach ($users as $user) {
        //
    }
});

回答3:

Hi I think this might help

    $users = User::groupBy('id')->orderBy('id', 'asc');

    $response = new StreamedResponse(function() use($users){
        $handle = fopen('php://output', 'w');
        // Add Excel headers
        fputcsv($handle, [
            'col1', 'Col 2'           ]);
        $users->chunk(1000, function($filtered_users) use($handle) {
            foreach ($filtered_users as $user) {
                // Add a new row with user data
                fputcsv($handle, [
                    $user->col1, $user->col2
                ]);
            }
        });
        // Close the output stream
        fclose($handle);
        }, 200, [
            'Content-Type' => 'text/csv',
            'Content-Disposition' => 'attachment; filename="Users'.Carbon::now()->toDateTimeString().'.csv"',
        ]);

        return $response;

来源：https://stackoverflow.com/questions/48643553/how-can-fetching-huge-records-using-laravel-and-mysql