我正在一个Laravel + Mongo DB项目中,我们在其中存储这样的数据:
_id | machinename | SoftwareKey | created_at
-----------------------------------------
5cf6c4a7fdce2778e833dd88 | VM007 | TestSoftware | 2017-01-30 13:22:39
-----------------------------------------
5cf6c4a7fdce2778e833324 | VM008 | TestSoftware | 2017-01-30 13:23:42
-----------------------------------------
5cf6c4a7fdce27783244355 | VM009 | TestSoftware | 2017-01-30 13:25:54
-----------------------------------------
5cf6c4a7fdce27723424345 | VM007 | TestSoftware | 2017-01-30 13:25:
-----------------------------------------
5cf6c4a7fdce23432432745 | VM008 | TestSoftware | 2017-01-30 13:25:54
-----------------------------------------
5cf6c4a7fdce27732467876 | VM009 | TestSoftware | 2017-01-30 13:25:33
我需要调整返回该表中所有条目的方法,以仅返回机器名称的最新条目,基本上是返回该部分:
_id | machinename | SoftwareKey | created_at
-----------------------------------------
5cf6c4a7fdce2778e833dd88 | VM007 | TestSoftware | 2017-01-30 13:22:39
-----------------------------------------
5cf6c4a7fdce2778e833324 | VM008 | TestSoftware | 2017-01-30 13:23:42
-----------------------------------------
5cf6c4a7fdce2778324 | VM009 | TestSoftware | 2017-01-30 13:25:54
索引方法:
public function index() {
$hills = Hill::all();
return fractal()
->collection($hills)
->transformWith(new HillTransformer)
->toArray();
}
我发现了this个问题,并尝试调整我的方法:
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use App\Hill;
use App\Transformers\HillTransformer;
use DB;
class HillController extends Controller
{
public function index() {
$hills = DB::select("SELECT *
FROM hills
JOIN (SELECT machinename, MAX(created_at) created_at
FROM hills
GROUP BY machinename) machinenames
ON machinename = machinenames.machinename
AND created_at = machinenames.created_at");
return fractal()
->collection($hills)
->transformWith(new HillTransformer)
->toArray();
}
}
但是我得到了这个例外:
“ message”:“对成员函数prepare()的调用为null”, “ exception”:“ Symfony \ Component \ Debug \ Exception \ FatalThrowableError”, “文件”:“ / home / vagrant / code / hilltracking / vendor / laravel / framework / src / Illuminate / Database / Connection.php”, “行”:326,
还有另一种方法可以做到这一点吗?谢谢!
顺便说一句。我正在使用laravel-mongodb和分形库。