如何在嵌入式文档中查找，嵌入式文档使用mongodb具有id

Question

I'm using mongoDb in my project, and I have problem using lookup on embedded data.. I searched for my problem and read similar codes.. but they didn't help my problem..

I mean in my embed document there is a variable named user that I want to load its data by lookup..

this is how my documents is:

"_id" : ObjectId("5d0f6a993702da22bc00474d"),
"quotes" : [
   {
     "amount" : NumberInt(100), 
     "user" : {
        "_id" : ObjectId("5cc69f7f46ab4cedda5c3c12")
     }, 
     "details" : "some quote details", 
     "_id" : ObjectId("5d0f6a993702da22bc00474c"), 
     "status" : "a"
    },
    {
      "amount" : NumberInt(120), 
      "user" : {
         "_id" : ObjectId("5cc69kij46ab4cedda5c3c12")
      }, 
      "details" : "some quote details 2", 
      "_id" : ObjectId("5d0f6a993702da22bc00484k"), 
      "status" : "a"
     }
],
"status" : "Approved", 
"title" : "gardening", 
"created_at" : NumberInt(1560841417)

so I want my output be like this:

"_id" : ObjectId("5d0f6a993702da22bc00474d"),
"quotes" : [
        {
            "amount" : NumberInt(100), 
            "user" : {
                "_id" : ObjectId("5cc69f7f46ab4cedda5c3c12"),
                "firstName": "John",
                "lastNAme": "Doe",
                "phone": 514298742
            }, 
            "details" : "some quote details", 
            "_id" : ObjectId("5d0f6a993702da22bc00474c"), 
            "status" : "a"
        },
        {
            "amount" : NumberInt(120), 
            "user" : {
                "_id" : ObjectId("5cc69kij46ab4cedda5c3c12")           
                "firstName": "Jane",
                "lastNAme": "Doe",
                "phone": 5148547642
            }, 
            "details" : "some quote details 2", 
            "_id" : ObjectId("5d0f6a993702da22bc00484k"), 
            "status" : "a"
        }
],
"status" : "Approved", 
"title" : "gardening", 
"created_at" : NumberInt(1560841417)

Answer 1

I found the solution.. this worked for me..

.aggregate([
  {
    {
      "$unwind": {
        "path": "$quotes",
        "preserveNullAndEmptyArrays": true
       }
    },
    {
       "$lookup": {
         "from": "users",
         "localField": "quotes.user._id",
         "foreignField": "_id",
         "as": "quotes.user",
        }
    },
    {
        "$unwind": {
           "path": "$quotes.user",
           "preserveNullAndEmptyArrays": true
         }
     },
     {
        "$group": {
           "_id": null,
           "quotes": {"$push": "$quotes"},
           "status": {"$first": "$status"},
           "title": {"$first": "$title"},
           "created_at": {"$first": "$created_at"},
         }
     },
  }
])

I posted my answer if anyone have the same issue.