Chunking results onto existing Object

I am facing an issue which I am looking to overcome. I have a Report that can have many different types of data sets. I have all relations set up appropriately.

Within my show function, when I need to pass this Object to the frontend I do

$dataArray = Report::with(['data_set_a', 'data_set_b', 'data_set_c'])
               ->where('user_id', Auth::user()->id)->where('id', $id)->first();

Now in most cases this works perfectly, data is passed to the frontend. However, for some reports, data_set_a has about 20k rows. Locally this is not a problem, but on my live system nothing loads.

I have checked the logs, and mod_security is stating inbound anomaly score exceeded. I imagine it is not liking the fact that the data set is large and it is blocking it.

As such, I was thinking about adding this data set manually using chunking. So I am attempting something like this

$dataArray = Report::with(['data_set_b', 'data_set_c'])
               ->where('user_id', Auth::user()->id)->where('id', $id)->first();

DataSetA::where('report_id', $report->id)
                ->chunk(500, function($data)  {
                    foreach ($data as $row) {
                            $dataArray['data_set_a'] = array(
                                'cust_id' => $row->cust_id,
                                'colOne' => $row->colOne,
                                'colTwo' => $row->colTwo,
                                'colThree' => $row->colThree
                            );
                        );
                    }
                });

However, I seem to be having issues with the syntax. How can I chunk this data from data_set_a onto the dataArray?

Thanks

via Chebli Mohamed