PHP MongoDB嵌套文档搜索

Question

I have a nested Document which have some language dependent content and I want to search if content have data for specific language and query should return me content else false.

I tried this query option

$data = $collection->findOne(array('original'=>'What is this', 'translation.language'=>'english') );

I am expecting this result:

{
       "language": "english",
       "quote": "What is this"
}

but above query return both language content. Can anyone please share some code also regarding saving and updating data using PHP

My collection:

{
   "_id": ObjectId("56a8844bc56760810e483815"),
   "language": "english",
   "original_key": "What is this",
   "translation": [
     {
       "language": "english",
       "quote": "What is this"
    },
     {
       "language": "spanish",
       "quote": "What is this Spanish"
    }
  ]
}   

Answer 1

Use the positional $ operator in the projection document of the findOne() method when you only need one particular array element in selected documents:

// search criteria for nested array
$query = array(
    'original' => 'What is this', 
    'translation.language' => 'english'
);

// projection (fields to include)
$projection =  array('_id' => false, 'translation.$' => true);

$result = $collection->findOne($query, $projection);
$data = $result->translation;
var_dump($data);