使用PHP中的MongoManager类查找集合中的所有文档

Question

I want to get data from all documents that are in Collection. In my case the data is Color field. I want to retrieve all the Color fields values from all documents that are in the Collection. Is it possible using MongoManager class in PHP? I am trying in this way;

 $mng = new MongoDB\Driver\Manager("mongodb://localhost:27017");
    $query = new MongoDB\Driver\Query([]);     
    $r = $mng->executeQuery("DB.Collection", $query);
    $R = current($r->toArray());

    if (!empty($R)) {
        echo ($R->Color);
    } else {
        echo "Nothing found";
    }

But it gives only one field. How can I get all color fields?

Answer 1

You can use distinct to get color field values from collection.

$mng = new MongoDB\Driver\Manager("mongodb://localhost:27017");
$cmd = new MongoDB\Driver\Command([
    'distinct' => Collection,
    'key' => 'color'
]);
$cursor = $mng->executeCommand(DB, $cmd);
$color = current($cursor->toArray())->values;