mongodb 将数据插入对象数组并更新它

Question

我要投票，它看起来像一个对象数组，看起来像用户的 ID 和他设置的值。

如果用户已经投票，但改变了他的值，你需要改变这个用户的对象数组中的 rate 值。

我需要创建一个对象数组，数据将像这样插入其中 {rate: 3, user: "asdr2r24f2f42f24"} 并且如果用户已经在这个数组中投票，那么您需要更改值 rate给定的用户

我已经尝试过做一些事情，但在我看来你可以写得更好，你能帮忙吗？

JSONhttps://jsoneditoronline.org/?id=442f1dae0b2d4997ac69d44614e55aa6

 router.post('/rating', (req, res) => {
  console.log(req.body)
  // { id: 'f58482b1-ae3a-4d8a-b53b-ede80fe1e225',
  //   rating: 5,
  //   user: '5e094d988ddbe02020e13879' }

  Habalka.find({
    _id: req.body.id
  })
    .then(habalka => {

      // here I need to check whether the user has already voted or not, and from this whether to add an object with it or update the number
      Habalka.updateOne(
        {_id: req.body.id},
        {$push: {rating: {rate: req.body.rating, user: req.body.user}}}
      )
        .then(e => {
          console.log(e)
        })
    });
});

架构

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

const HabalkaSchema = new Schema({
  _id: {
    type: String
  },
  bio: {
    firstname: String,
    lastname: String,
    middlename: String,
    company: String
  },
  rating: [

  ],
  files: [
    {
      _id: {
        type: String
      },
      destination: {
        type: String
      },
      filename: {
        type: String
      },
      path: {
        type: String
      },
      folder: {
        type: String
      },
      info: {
        size: {
          type: Number
        },
        mimetype: {
          type: String
        },
        encoding: {
          type: String
        },
        originalname: {
          type: String
        },
        fieldname: {
          type: String
        },
      },
      date: {
        type: Date,
        default: Date.now
      },
      bio: {
        type: Object
      },
      userId: String,
      guessId: {},
    }
  ],
  date: {
    type: Date,
    default: Date.now
  }
});
module.exports = Habalka = mongoose.model('habalka', HabalkaSchema);

Answer 1

这是一个聚合查询，它在rating 数组中插入一个新用户或更新现有用户的评分： 示例代码的req.body.id、req.body.user和req.body.rating设置如下：

var ID = 1, INPUT_USER = "new user", INPUT_RATE = 5;

const matchStage = { $match: { _id: ID } };
const facetStage = {
  $facet: {
      new_user: [
        { $match: { "rating.user": { $not: { $eq: INPUT_USER } } } },
        { $addFields: { rating: { $concatArrays: [ "$rating", [ { user: "new user", rate: INPUT_RATE } ] ] } } },
      ],
      user: [   
        { $match: { "rating.user": INPUT_USER } },
        { $addFields: { 
               rating: {
                   $map: { 
                       input: "$rating",
                       as: "r",
                       in: {
                       $cond: [ { $eq: [ "$$r.user", INPUT_USER ] },
                                { user: "$$r.user", rate: { $add: [ "$$r.rate", INPUT_RATE ] } },
                                "$$r"
                              ]
                       }
                   }
               }
        } }
      ]
  }
};
const projectStage = { 
     $project: { 
         result: { $arrayElemAt: [ { $concatArrays: [ "$user", "$new_user" ] }, 0 ] }  
     }
};

const queryPipeline = [
    matchStage,
    facetStage,
    projectStage
];

// Run the aggregation query and get the modified document
// after applying the user and rate data in the rating array.
// The result of the aggregation is used to update the collection.
col.aggregate(queryPipeline).toArray( ( err, docs ) => {

    console.log("Aggregation output:");
    console.log( JSON.stringify( docs[0] ) );

    // Update the aggregate result to the collection.
    col.updateOne( { _id: docs[0].result._id },
                   { $set: { rating: docs[0].result.rating } }, 
                   ( err, updateResult ) => {
                       console.log( 'Updated count: ', updateResult.matchedCount );
                    }
     );

     callback(docs);
} );

示例集合文档：

{ "_id" : 1, "rating" : [ { "user" : "user1", "rate" : 2 } ] }

如果输入是var ID = 1, INPUT_USER = "new user", INPUT_RATE = 5;，更新后的文档将是：

{ "_id" : 1, "rating" : [ { "user" : "user1", "rate" : 2 }, { "user" : "new user", "rate" : 5 } ] }

如果输入是var ID = 1, INPUT_USER = "user1", INPUT_RATE = 5;，更新后的文档将是：

{ "_id" : 1, "rating" : [ { "user" : "user1", "rate" : 7 } ] }