从JSON中获取对象属性值

I am getting this returned to me:

{
"GROUP_CONCAT(DISTINCT(CONCAT(\"MAX(IF(pa.printer = \"\"\", printer, \"\"\", pa.printer, NULL)) AS \", printer)))":
 "MAX(IF(pa.printer = \"JP4-3\", pa.printer, NULL)) AS JP4-3,MAX(IF(pa.printer = \"JP4-1\", pa.printer, NULL)) AS JP4-1,MAX(IF(pa.printer = \"JP4-2\", pa.printer, NULL)) AS JP4-2,MAX(IF(pa.printer = \"B3\", pa.printer, NULL)) AS B3,MAX(IF(pa.printer = \"A2\", pa.printer, NULL)) AS A2"
    }

I want to get the value of this but just the string. I can't get it out of the {}. This should be so simple but cant find an answer anywhere.

BELOW IS JUST REFERENCE TO WHAT I AM DOING

The main goal is a MySQL pivot table. Takes 2 calls but I am OK with that.

$listQuery = PrintJob::select(DB::raw('GROUP_CONCAT(DISTINCT(CONCAT("MAX(IF(pa.printer = """, printer, """, pa.printer, NULL)) AS ", printer)))'))->get();

This is returning the result above:

    $json = $listQuery[0];

Then going to use it in this query

    $data = PrintJob::select(DB::raw('DATE(calendar.datefield) as date'), DB::raw('SUM(print_jobs.quantity) as sum'), DB::raw($listQuery))
                ->leftJoin('mo_numbers', 'mo_numbers.mo_id', '=', 'print_jobs.mo_id')
                ->rightJoin('calendar', 'calendar.datefield', '=', 'print_jobs.job_date')
                ->whereDate('calendar.datefield', '>=', date($from))
                ->whereDate('calendar.datefield', '<=', date($to))
                ->groupBy('date')
                ->toSql();
                //->get();

That's some weird stuff to get, however this will get the value:

$value = current(json_decode($json, true));

To get the key:

$key = key(json_decode($json, true));

Or in one swoop:

list($key, $val) = each(json_decode($json, true));