The Query.prototype.mod() function is used to specify a $mod condition. This function basically filters documents for documents whose path property is a number that is equal to remainder modulo divisor.
Syntax:
Query.prototype.mod()
Parameters: This function has one optional path parameter and an array parameter which must be of length 2 where the first element is the divisor and the second element is the remainder.
Return Value: This function returns Query Object.
Mongoose Installation:
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:
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.find().mod( 'age' , [2, 0]);
query.exec( function (err, res){
if (err) console.log(err)
else console.log(res)
}); |
The project structure will look like this:
Run index.js file using below command:
node index.js
Output:
[ { _id: 5ebb9129a99bde77b2efb809, name: 'Gourav', age: 10, __v: 0 }, { _id: 5ebd345f5d2d8a3534b2f391, name: 'Manish', age: 34, __v: 0 } ]
Example 2:
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.find().mod( 'age' , [2, 1]);
query.exec( function (err, res){
if (err) console.log(err)
else console.log(res)
}); 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 [ { _id: 5ebc3669a99bde77b2efb9ba, name: 'Lalit', age: 25, __v: 0 }, { _id: 5ebc367da99bde77b2efb9bf, name: 'Piyush', age: 5, __v: 0 } ]
Reference: https://mongoosejs.com/docs/api/query.html#query_Query-mod