How does Query.prototype.circle() works in Mongoose ?
The Query.prototype.circle() function is used to specify a $center or $centerSphere condition. It specifies a circle for a $geoWithin query.
Syntax:
Query.prototype.circle()
Parameters: This function has one area parameter and one optional path parameter.
Return Value: This function returns Query Object.
Installing mongoose:
npm install mongoose
After installing the mongoose module, you can check your mongoose version in command prompt using the command.
npm mongoose --version
Database: The sample database used here is shown below.
Folder Structure:
Now, create a folder and add a file, for example, index.js as shown below.
Example 1:
index.js
const mongoose = require( 'mongoose' ); // Database connection mongoose.connect( 'mongodb://127.0.0.1:27017/w3wiki' , { useNewUrlParser: true , useCreateIndex: true , useUnifiedTopology: true }); // User model const User = mongoose.model( 'User' , { name: { type: String }, age: { type: Number } }); var query = User.find(); var area = { center: [20, 20], radius: 5, unique: true } query.where( 'loc' ).within().circle(area) console.log(query._conditions.loc.$geoWithin) |
Run index.js file using below command:
node index.js
Output:
{ '$center': [ [ 20, 20 ], 5 ], '$uniqueDocs': true }
Example 2:
index.js
const express = require( 'express' ); const mongoose = require( 'mongoose' ); const app = express() // Database connection mongoose.connect( 'mongodb://127.0.0.1:27017/w3wiki' , { useNewUrlParser: true , useCreateIndex: true , useUnifiedTopology: true }); // User model const User = mongoose.model( 'User' , { name: { type: String }, age: { type: Number } }); var query = User.find(); var area = { center: [2, 2], radius: 15, unique: true } query.where( 'loc' ).within().circle(area) console.log(query._conditions.loc.$geoWithin) app.listen(3000, function (error ) { if (error) console.log(error) console.log( "Server listening on PORT 3000" ) }); |
Run index.js file using below command:
node index.js
Output:
Server listening on PORT 3000 { '$center': [ [ 2, 2 ], 15 ], '$uniqueDocs': true }
Reference:
https://mongoosejs.com/docs/api/query.html#query_Query-circle