Question

我在项目中使用mongoDb，在对嵌入式数据进行查找时遇到问题..我搜索了问题并读取了类似的代码..但它们对我的问题没有帮助。

我的意思是我的嵌入文档中有一个名为user的变量，我想通过查找来加载其数据。

这是我的文档的样子：

"_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)

所以我希望我的输出是这样的：

"_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

我找到了解决方案..这对我有用。

.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"},
         }
     },
  }
])

如果有人遇到同样的问题，我会发布答案。

如何使用mongodb在嵌入式文档中查找并且该嵌入式文档具有ID

1 个答案: