请问这样得查询如何做呢？

Question

{
    "_id" : ObjectId("5f5f1441d24b630fa4b8026b"),
    "look_num" : 0,
    "is_stick" : 0,
    "status" : "1",
    "title" : "3",
    "content_text" : "3",
    "content_html" : "3",
    "tag" : [ 
        {
            "_id" : ObjectId("5f5f1441d24b630fa4b8026c"),
            "tag_id" : ObjectId("5f51e982a17d7739a435ec76")
        }, 
        {
            "_id" : ObjectId("5f5f1441d24b630fa4b8026d"),
            "tag_id" : ObjectId("5f5eef55c4aa721ed43bb954")
        }
    ],
    "createTime" : ISODate("2020-09-14T06:57:05.107Z"),
    "updateTime" : ISODate("2020-09-14T06:57:05.107Z")
}

已知一个tag_id,如何这个表里面tag中有该tag_id的所有数据呢，请大佬讲讲呀

Answer 1

db.getCollection('collection_name').find({ "tag": { $elemMatch: { "tag_id": _id_  } } })