如何在mongodb中删除子对象答案

【问题标题】：how to remove child object in mongodb如何在mongodb中删除子对象
【发布时间】：2019-09-25 16:57:30
【问题描述】：

下面是我在 mongodb 中的 json 存储

[
  {
    "type": "mailbox",
    "id": 0,
    "name": "Suresh Adling",
    "mailBoxType": "private",
    "children": [
      {
        "id": 1,
        "name": "Inbox",
        "type": "folder",
        "mailBoxType": "private",
        "children": [],
        "userName": "suresh.adling",
        "canEdit": false
      },
      {
        "id": 2,
        "name": "Deleted Items",
        "type": "folder",
        "mailBoxType": "private",
        "children": [],
        "userName": "suresh.adling",
        "canEdit": false
      },
      {
        "id": "fc761eaa-e2c8-493f-91d3-04d38c730534",
        "name": "vishal patil_deactivated",
        "mailBoxType": "private",
        "type": "Folder",
        "children": [
          {
            "id": "214f08d7-32e1-4871-aa1d-2c923882a302",
            "name": "Inbox",
            "type": "Folder",
            "mailBoxType": "private",
            "children": [],
            "userName": "suresh.adling",
            "canEdit": false
          },
          {
            "id": "fb91e540-1b23-438a-a1b3-7a08d0a60fbf",
            "name": "Deleted Items",
            "type": "Folder",
            "mailBoxType": "private",
            "children": [],
            "userName": "suresh.adling",
            "canEdit": false
          }
        ],
        "userName": "suresh.adling",
        "canEdit": false
      },
      {
        "id": "1d172869-18b4-4c11-a8bf-e162ec0fd260",
        "name": "swapnil N_deactivated",
        "mailBoxType": "private",
        "type": "Folder",
        "children": [
          {
            "id": "b5b86995-43e6-4798-ad94-20f2598a2cf1",
            "name": "Inbox",
            "type": "Folder",
            "mailBoxType": "private",
            "children": []
          },
          {
            "id": "13f384ea-c2f6-48c3-a67f-dc712b7917a8",
            "name": "Deleted Items",
            "type": "Folder",
            "mailBoxType": "private",
            "children": []
          }
        ]
      }
    ],
    "userName": "suresh.adling",
    "canEdit": false
  }
]

并在下面对象的这个json中删除数据库

{
        "id": "fc761eaa-e2c8-493f-91d3-04d38c730534",
        "name": "vishal patil_deactivated",
        "mailBoxType": "private",
        "type": "Folder",
        "children": [
          {
            "id": "214f08d7-32e1-4871-aa1d-2c923882a302",
            "name": "Inbox",
            "type": "Folder",
            "mailBoxType": "private",
            "children": [],
            "userName": "suresh.adling",
            "canEdit": false
          },
          {
            "id": "fb91e540-1b23-438a-a1b3-7a08d0a60fbf",
            "name": "Deleted Items",
            "type": "Folder",
            "mailBoxType": "private",
            "children": [],
            "userName": "suresh.adling",
            "canEdit": false
          }
        ],
        "userName": "suresh.adling",
        "canEdit": false
      },

如何删除rest api node js以及如何在node中创建这些api？

我是这个领域的新手。我想要正常的成功消息

【问题讨论】：

标签： javascript node.js mongodb rest

【解决方案1】：

我认为您搜索了 $pull 运算符，您必须提供匹配的查询，例如要删除的数组元素的 id，更多在 mongodb 文档中。 https://docs.mongodb.com/manual/reference/operator/update/pull/#up._S_pull

我在 mongoDB 中有我的 stores 集合，我创建了 store：

    {
    "children": [
        {
            "id": "First child",
            "value": 5
        },
        {
            "id": "Second child",
            "value": 10
        },
        {
            "id": "Third child",
            "value": 15
        },
        {
            "id": "Fourth child",
            "value": 20
        }
    ],
    "_id": "5d8b28c13ff93437f875d263",
    "name": "Johnny",
    "color": "Blue",
    "__v": 0
}

在 nodeJS 中我创建了 store 模型：

const mongoose = require('mongoose');

const Schema = mongoose.Schema;

const StoreSchema = new Schema({
    name: {
        type: String,
        required: true
    },
    color: {
        type: String,
        required: true
    },
    children: {
        type: Array,
        required: true
    }
});

const Store = mongoose.model('stores', StoreSchema);

module.exports = Store

以及删除它的孩子的方法：

    router.delete("/children", async (req,res) =>{
    const {storeId, childId} = req.query
    const query = Store.update({ _id: storeId },{ $pull: { children: { id: childId}}});
    try {
        const result = await query.exec()
        res.status(200).send(result)
    } catch (err){
        res.send(err)
    }
})

从 postman 调用 API 后： Screenshot of API call

Store 对象已更新，现在看起来像这样：

{ 
   "_id":"5d8b282a9fb35d0714c37550",
   "children":[ 
      { 
         "id":"Second child",
         "value":10
      },
      { 
         "id":"Third child",
         "value":15
      },
      { 
         "id":"Fourth child",
         "value":20
      }
   ],
   "name":"Johnny",
   "color":"Blue",
   "__v":0
}

【讨论】：