How do I extract subdocument in laravel mongodb

Question

Hello Good Developers,

I am using jenssegers/laravel-mongodb package to query my MongoDB from Laravel.

Here's Fiddle for my query: https://mongoplayground.net/p/qzbNN8Siy-3

I have following JSON

[{
    "id": "GLOBAL_EDUCATION",
    "general_name": "GLOBAL_EDUCATION",
    "display_name": "GLOBAL_EDUCATION",
    "profile_section_id": 0,
    "translated": [
      {
        "con_lang": "US-EN",
        "country_code": "US",
        "language_code": "EN",
        "text": "What is the highest level of education you have completed?",
        "hint": null
      },
      {
        "con_lang": "US-ES",
        "country_code": "US",
        "language_code": "ES",
        "text": "\u00bfCu\u00e1l es su nivel de educaci\u00f3n?",
        "hint": null
      }...
    {
     ....
    }
]

I am trying to run following command

db.collection.find({ 'id': "GLOBAL_EDUCATION" },{_id:0, id:1, general_name:1, translated:{ $elemMatch: {con_lang: "US-EN"} }})

Expecting result like this

[
  {
    "general_name": "GLOBAL_EDUCATION",
    "id": "GLOBAL_EDUCATION",
    "translated": [
      {
        "con_lang": "US-EN",
        "country_code": "US",
        "hint": null,
        "language_code": "EN",
        "text": "What is the highest level of education you have completed?"
      }
    ]
  }
]

Everything is fine while query directly in MoDB but issue arise when I am trying this in Laravel. I've tried every possible known function from MongoDB package. but Not able to do this. here's my Array

$findArray = [
        [
            'id' => "GLOBAL_EDUCATION",
        ],
        [
            '_id' => 0,
            'id' => 1,
            'general_name' => 1,
            'translated' => [
                '$elemMatch' => ['con_lang' => "US-EN"]
            ],
        ]
];

$model = GlobalQuestions::raw()->find($findArray) //OR
$data = GlobalQuestions::raw(function($collection) use ($findArray){
        return $collection->find($findArray);
});

What I am doing wrong here, is this kind of Find() not possible here and I've to do this by aggregation?

When I run the first find I am getting a Blank Cursor Object and when I am running the second kind of find, I am getting Blank Collection — Pankaj Jha, Feb 01 '19 at 13:18
I am able to get data using aggregation and Pipelines using following function `GlobalQuestions::raw(function($collection) { return $collection->aggregate([]) });` But I don't want to use aggregation over normal find query — Pankaj Jha, Feb 01 '19 at 13:25
try printing this: `print_r(iterator_to_array($data));` in the last line of your code in the question — Archit Saxena, Feb 01 '19 at 14:14
It returns blank array, tried Iterating, Hydrating and Looping — Pankaj Jha, Feb 01 '19 at 14:18

score 2 · Accepted Answer · answered Feb 04 '19 at 17:16

Since no-one answered this, I am posting the solution if someone is having the same issue. Doing some more R&D on the same I was able to do this using where and Project as well by Aggregation Pipelines.

----- Using Where() and Project() ------

$projectArray = [
    '_id' => 0,
    'id' => 1,
    'general_name' => 1,
    'translated' => [
        '$elemMatch' => ['con_lang' => "FR-FR"]
    ],
];

$data = GlobalQuestions::where('id', '=', 'GLOBAL_EDUCATION')
    ->project($projectArray)
    ->get();

--- Using Aggregation and $unwind ---

$data = GlobalQuestions::raw(function($collection) {
    return $collection->aggregate([
        [
            '$match' => [
                'id' => "GLOBAL_EDUCATION"
            ]
        ],
        [
            '$unwind' => '$translated',
        ],
        [
            '$match' => [
                'translated.con_lang' => "US-EN"
            ]
        ],
        [
            '$project' => [
                '_id'=> 0,
                'id'=> 1,
                'general_name' => 1,
                'translated' => 1,
            ]
        ]
    ]);
})->first();

How do I extract subdocument in laravel mongodb

1 Answers1