MongoDB and Nodejs insert ID with auto increment - node.js

Question

I am new to NodeJs and MongoDB, i want to insert row with auto increment primary key 'id'. also defined a function called getNextSequence on mongo server.
this is working perfect on Mongodb server
> db.user.insert({
"id" : getNextSequence('user_id'),
"username" : "test",
"email" : "test#test.com",
"password" : "test123"
})
now i want to insert from NodeJs.I have tried this but not working
db.collection('user').insertOne({
id : "getNextSequence('user_id')",
username : query.name,
email: query.email,
password: query.pass
}, function(err, result) {
assert.equal(err, null);
console.log("row insterted ");
callback();
});

Answer 1

Assuming that getNextSequence is a server-script function (i.e. a method you defined and saved via db.system.js.save), it is not callable outside of the server. One way to go is to use eval, which forces the server to evaluate a string as a js code, even though it is not a good practice. Here is an example:
db.eval('getNextSequence(\'user_id\')', function(err, result) {
db.collection('users').insert({
"id" : result,
"username" : "test",
"email" : "test#test.com",
"password" : "test123"
});
});
Another way is to follow the mongo tutorial and to implement the getNextSequence directly in NodeJS. The syntax is pretty much the same:
function getNextSequence(db, name, callback) {
db.collection("counters").findAndModify( { _id: name }, null, { $inc: { seq: 1 } }, function(err, result){
if(err) callback(err, result);
callback(err, result.value.seq);
} );
}
You then use it in your nodeJS code like:
getNextSequence(db, "user_id", function(err, result){
if(!err){
db.collection('users').insert({
"_id": result,
// ...
});
}
});
Note: of course, you need to have set the counters collection as explained in the docs.

Answer 2

You can also use "mongoose-auto-increment".
The code has just 4 lines
var mongoose = require('mongoose');
var autoIncrement = require('mongoose-auto-increment');
autoIncrement.initialize(mongoose.connection);
userSchema.plugin(autoIncrement.plugin, 'user');
example :
npm i mongoose-auto-increment
connections.js :
const mongoose = require('mongoose');
require("dotenv").config;
const uri = process.env.MONGOURL;
mongoose.connect(uri, { useNewUrlParser: true }, (err) => {
if (!err) { console.log('MongoDB Connection Succeeded.') }
else { console.log('Error in DB connection : ' + err) }
});
require('../schema/userSchema');
userSchema.js :
var mongoose = require('mongoose'); // 1. require mongoose
var autoIncrement = require('mongoose-auto-increment'); // 2. require mongoose-auto-increment
var userSchema = new mongoose.Schema({
name: { type: String },
password: { type: String },
email: { type: String, unique: true, required: 'This field is required.' },
});
autoIncrement.initialize(mongoose.connection); // 3. initialize autoIncrement
userSchema.plugin(autoIncrement.plugin, 'user'); // 4. use autoIncrement
mongoose.model('user', userSchema);

Answer 3

To accomplish this, we will create a function that will keep trying to save the document untill it will have been saved with incremented _id
async function retryUntilSave(db, task) {
try {
const index = await db.collection('tasks').find().count() + 1;
const result = await db.collection('tasks').insertOne(Object.assign(task, { _id: index }))
} catch (error) {
if (error.message.includes("_id_ dup key")) {
console.log("ID already exists!")
console.log("Retrying...");
retryUntilSave(db, task)
} else {
console.log(error.message);
}
}
}
We can use task._id: index instead of Object.assign()
finally you can test this by making some concurrent requests
for (let index = 0; index < 20; index++) {
setTimeout(async () => {
await retryUntilSave(db, { title: "Some Task" })
}, 1000);
}
This function will handle easily if two or more tasks submitted at the same time because mogod throws error when we try to insert a document with duplicate _id, then we will retry saving the document again with incremented _id and this process will run until we save the document successfully !

Answer 4

You can also use "mongodb-autoincrement" module of node js. For example:
var autoIncrement = require("mongodb-autoincrement");
exports.yourMethod = function(newData, callback) {
autoIncrement.getNextSequence(db, your-collection-name, function (err, autoIndex) {
newData.id = autoIndex;
//save your code with this autogenerated id
});
}

Answer 5

You can use the below package on a model schema to auto-increment your collection field.
mongoose-auto-increment //you can download it from npm
Here I am not focusing on how to connect MongoDB. I just focus on how you can integrate auto increment in your model/collection/table.
const mongoose = require("mongoose"); //
const autoIncrement = require("mongoose-auto-increment");
const post_schema = new mongoose.Schema({
title: {
type: String,
required: true,
min: 3,
max: 225,
},
slug: {
type: String,
required: true,
},
});
autoIncrement.initialize(mongoose.connection);
post_schema.plugin(autoIncrement.plugin, {
model: "post", // collection or table name in which you want to apply auto increment
field: "_id", // field of model which you want to auto increment
startAt: 1, // start your auto increment value from 1
incrementBy: 1, // incremented by 1
});
module.exports = mongoose.model("post", post_schema);