MongoDB中JSON数组无序保存使用mongoose的.save()方法

Question

I need to save a long JSON array in a collection in a free MongoDB database.

For that I connect to my database via mongoose then I make a for loop which will read each JSON of my array and save it with the good model in the good collection thanks to the save() method of mongoose . I make this connection in an application that uses node and the express framework.

This is the following code, which I tried to simplify, that does this:

 const data = [
  {
    "numero": 1531,
    "annee": 2022,
    "date": "22/05/2022",
    "premier_cas": 10
  },
  {
    "numero": 1532,
    "annee": 2022,
    "date": "29/05/2022",
    "premier_cas": 15
  }
//MANY THOUSANDS OF OBJECT
];

const mongoose = require('mongoose');
mongoose.Promise = global.Promise;
const db = {};
db.mongoose = mongoose;
db.result = require("./result.model");

const Result = db.result;

db.mongoose
  .connect(process.env.MONGODB_URI, {
    useNewUrlParser: true,
    useUnifiedTopology: true
  })
  .then((client) => {
    console.log("Successfully connect to MongoDB.");
    addResultToCollection();
  })
  .catch(err => {
    console.error("Connection error", err);
    process.exit();
  });

function addResultToCollection() {
  Result.estimatedDocumentCount(async (err, count) => {
    if (!err && count === 0) {
      for (let i = 0; i < data.length; i++) {
        await createAndSaveOneResult(data[i], i);
      }
    } else if (count !== 0) {
      console.log("Results have already been created!");
    }
  });
}

async function createAndSaveOneResult(json, counter) {
  new Result({
    numero: json.numero,
    annee: json.annee,
    date: json.date,
    premier_cas: json.cas
  }).save(err => {
    if (err) {
      console.log("error", err);
    }
    console.log("Results %d a été créé", counter);
  });
}

My model Result is the following :

const mongoose = require('mongoose');

const Result = mongoose.model(
    "Result",
    (new mongoose.Schema({
        numero: {
            type: Number,
            required: 'This field is required'
        },
        annee: {
            type: Number,
            required: 'This field is required'
        },
        date: {
            type: String,
            required: 'This field is required'
        },
        premier_cas: {
            type: Number,
            required: 'This field is required'
        },
    })).index({ "$**": 'text' })
);

module.exports = Result;

This code allows me to connect to my database and save the thousands of JSONs that are contained in my array. The problem is that the recording is not done in the right order, when I display the number of the object created in my terminal at the time of its creation I get this :

...
Results 947 a été créé
Results 942 a été créé
Results 988 a été créé
Results 995 a été créé
Results 994 a été créé
Results 1000 a été créé
Results 997 a été créé
Results 996 a été créé
Results 987 a été créé
Results 990 a été créé
Results 991 a été créé
Results 989 a été créé
Results 992 a été créé
Results 993 a été créé
Results 1003 a été créé
Results 1001 a été créé
Results 999 a été créé
Results 998 a été créé
Results 1004 a été créé
Results 1002 a été créé
Results 1007 a été créé
Results 986 a été créé
Results 1020 a été créé
Results 1011 a été créé
...

When I look at the new objects registered in my MongoDB collection they are also in disorder,, so it's not a timing issue because of the local console.log() which would fail to keep up with the saving in MongoDB.

To solve this problem and put my objects in the right order I tried to use async/await logic to wait for the save() method to be performed before saving the next object, this is what I did in the code above. But the problem remained the same.

I also tried to put a setTimeOut() in my for loop to wait two seconds between each object registration, this is the following code but the problem remained the same.

db.mongoose
  .connect(process.env.MONGODB_URI, {
    useNewUrlParser: true,
    useUnifiedTopology: true
  })
  .then((client) => {
    console.log("Successfully connect to MongoDB.");
    addResultToCollection();
  })
  .catch(err => {
    console.error("Connection error", err);
    process.exit();
  });

function addResultToCollection() {
  Result.estimatedDocumentCount(async (err, count) => {
    if (!err && count === 0) {
      for (let i = 0; i < data.length; i++) {
        setTimeout(() => {
          new Result({
            numero: data[i].numero,
            annee: data[i].annee,
            date: data[i].date,
            premier_cas: data[i].premier_cas
          }).save(err => {
            if (err) {
              console.log("error", err);
            }
            console.log("Results %d a été créé", i);
          });
        }, "2000")
      }
    } else if (count !== 0) {
      console.log("Results have already been created!");
    }
  });
}

If anyone knows how to fix this problem and get the objects in the array to save in the right order it would be a great help.

Answer 1

I found my problem, I was using the wrong mongoose method. save() saves one document and insertMany() saves multiple documents.

The code that works:

const db = require("./models");
const Role = db.role;
const Result = db.result;
db.mongoose
  .connect(process.env.MONGODB_URI, {
    useNewUrlParser: true,
    useUnifiedTopology: true
  })
  .then((client) => {
    console.log("Successfully connect to MongoDB.");
    addResultToCollection();
  })
  .catch(err => {
    console.error("Connection error", err);
    process.exit();
  });
 
function addResultToCollection() {
  Result.estimatedDocumentCount(async (err, count) => {
    if (!err && count === 0) {
      Result.insertMany(data)
        .then(function () {
          console.log("Data inserted")
        }).catch(function (error) {
          console.log(error)
        });
    } else if (count !== 0) {
      console.log("Results have already been created!");
    }
  });
}