node.js - 如何使用mongoose插入嵌套文档帖子有很多评论，评论有很多回复

Question

我的帖子文档具有以下结构:

{
    "_id" : ObjectId("5d9df11b0e0a6e032bf3117f"),
    "body" : "Sample content post.",
    "date" : ISODate("2019-10-07T11:02:40.126Z"),
    "comments" : [            
        {
            "comment" : "comment on post",
            "_id" : ObjectId("5d9df46e0e0a6e032bf31182"),
            "replies" : [
                { 
                    "reply" : "reply to comment ",
                    "_id" : ObjectId("5d9bec26301798056bb07ab5")
                },
                      ]
        }, 
    ],

}

我想为此请求数据的特定帖子和评论添加新的回复{data: req.body}

{
  "data": {
    "id_post": "5d9df11b0e0a6e032bf3117f",
    "id_comment": "5d9df46e0e0a6e032bf31182",
    "new_reply": "Another new reply to comment"
  }
}

我正在使用nodejs/express/mongoose，你能指导我如何添加新回复吗？

   router.post("/saveReply", function(req, res, next){
     const query = Post.findById(req.body.id_post);
     const updatePost = async () => {
      try {
          await Post.updateOne(
              {
                  "_id": req.body.id_post,
                  "comments._id": req.body.id_comment
              },
              {
                  "$push": {
                      "comments.$.replies": {
                          "reply": req.body.reply,
                      }
                  }
              },
          );
      }
      catch (error) {
          console.log('💥', error);
      }
  };

  updatePost().then(() => console.log('✅Post updated successfully!'));

});

Answer 1

您可以使用更新操作和位置$运算符来完成此用例。

示例:

app.js 添加 mongoose 连接

const mongoose = require('mongoose');

const dbURI = 'mongodb://localhost:27017/post'

mongoose.Promise = global.Promise;

mongoose.connection.openUri(config.dbURI);

mongoose.connection.on('connecting', () => {
    console.log('connecting to MongoDB...');
});

mongoose.connection.on('connected', () => {
    console.log('Mongoose default connection open to ' + config.dbURI);
});

mongoose.connection.on('error', (err) => {
    console.log('Mongoose default connection error: ' + err);
});

mongoose.connection.on('disconnected', () => {
    console.log('Mongoose default connection disconnected');
    mongoose.connect(dbURI, {server: {auto_reconnect: true}});
});

post.js模型文件

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const ObjectId = Schema.ObjectId;

let postSchema = new Schema({
        body: String,
        date:Date,
        comments : Array
    }
);


let postCollection = mongoose.model('posts', postSchema);

module.exports = postCollection;

在API中

let post = require('post-model-file');


let addReply = async ()=>{

  try{
       await post.update(
             {
               "_id" : ObjectId("5d9df11b0e0a6e032bf3117f"),
               "comments._id" :ObjectId("5d9df46e0e0a6e032bf31182") 
             },
            {
            "$addToSet" : { 
                "comments.$.replies" : {
                            "reply" : "reply to comment ",
                            "_id" : ObjectId("5d9bec26301798056bb07ac5")
                               }
                          }
            }
    );
}
catch(e){

console.error(e)
}
}

欲了解更多信息，请查看https://docs.mongodb.com/manual/reference/operator/update/positional/