Question

我的收藏是这样的：

{
"_id" : ObjectId("590886af47627f86e5857141"),
"code" : "MY",
"pre_title" : "republic of",
"name" : "Malaysia",
"topics" : [ 
    {
        "name" : "overview",
        "body" : "ergergerg123234",
        "type" : "info",
        "_id" : ObjectId("5931243d26fca3496dbffe92"),
        "facts" : [ 
            {
                "key" : "capital",
                "value" : "Kuala Lumpur",
                "_id" : ObjectId("5931243d26fca3496dbffe96")
            }, 
            {
                "key" : "population",
                "value" : "232424234",
                "_id" : ObjectId("5931243d26fca3496dbffe95")
            }, 
            {
                "key" : "reliogion",
                "value" : "Islam",
                "_id" : ObjectId("5931243d26fca3496dbffe94")
            }, 
            {
                "key" : "government_form",
                "value" : "Federal constitutional monarchy",
                "_id" : ObjectId("5931243d26fca3496dbffe93")
            }
        ]
    }, 
    {
        "name" : "Good to know",
        "body" : "here in good to know",
        "type" : "info",
        "_id" : ObjectId("5931243d26fca3496dbffe90"),
        "facts" : [ 
            {
                "key" : "key1",
                "value" : "value1",
                "_id" : ObjectId("5931243d26fca3496dbffe91")
            }
        ]
    }
]
}

我需要访问topicId =“X”和countryId = _id的主题。我写这行但结果是错误的：所以它有两个条件。第一个countryId应匹配然后TopicId

  var query = {"_id":_id,"topics.$._id": topicId }
   Country.findOne(query ,function (err, topic) {

    console.log('topic',topic);
})

更新：

它的工作方式与此类似，但我还需要了解key = {XX}

的内容

Country.findById(query).select({ topics: { $elemMatch: { _id: topicId } 
} }).
  .then((topic,err) => {

Answer 1

var query = {"_id":_id,"topics._id": topicId }
 Country.findOne(query,{topics.$:1} ,function (err, topic) {

   console.log('topic',topic);
})

从查询中删除$使用topic._id而不是主题。$ ._ id

mongoose嵌套数据数组

1 个答案: