The Query.prototype.j() function is used to request acknowledgement that this operation has been persisted to MongoDB’s on-disk journal.
Syntax:
Query.prototype.j()
Parameters: This function has one val parameter of boolean type.
Return Value: This function returns Query Object.
Installing mongoose :
npm install mongoose
After installing the mongoose module, you can check your mongoose version in command prompt using the command.
npm mongoose --version
After that, you can just create a folder and add a file for example, index.js as shown below.
Database: The sample database used here is shown below:
Example 1:
Filename: index.js
const mongoose = require( 'mongoose' );
// Database connection useNewUrlParser: true ,
useCreateIndex: true ,
useUnifiedTopology: true
}); // User model const User = mongoose.model( 'User' , {
name: { type: String },
age: { type: Number }
}); const query = User.updateOne({name: "Gourav" }, { $set: {name: 'Geek' } }).j( true );
console.log( "Above operation has been persisted to MongoDB's on-disk journal" )
|
The project structure will look like this:
Run index.js file using below command:
node index.js
Output:
Above operation has been persisted to MongoDB's on-disk journal
Example 2:
Filename: index.js
const express = require( 'express' );
const mongoose = require( 'mongoose' );
const app = express() // Database connection useNewUrlParser: true ,
useCreateIndex: true ,
useUnifiedTopology: true
}); // User model const User = mongoose.model( 'User' , {
name: { type: String },
age: { type: Number }
}); const query = User.updateOne({name: "Gourav" }, { $set: {name: 'Geek' } }).j( false );
console.log( "Above operation has not been persisted to MongoDB's on-disk journal" )
app.listen(3000, function (error ) {
if (error) console.log(error)
console.log( "Server listening on PORT 3000" )
}); |
The project structure will look like this:
Run index.js file using below command:
node index.js
Output:
Server listening on PORT 3000 Above operation has not been persisted to MongoDB's on-disk journal
Reference:
https://mongoosejs.com/docs/api/query.html#query_Query-j