How does Query.prototype.centerSphere() work in Mongoose ?
The Query.prototype.centerSphere() function defines a circle for a geospatial query that uses spherical geometry. It returns the all the documents which are within the bounds of the circle.
Syntax:
Query.prototype.centerSphere()
Parameters: This function has one value parameter, and an 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
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().centerSphere(area) console.log(query._conditions.loc.$geoWithin) |
- The project structure will look like this:
node index.js
Output :
{ '$centerSphere': [ [ 20, 20 ], 5 ], '$uniqueDocs': true }
Example 2:
index.js
const express = require( 'express' ); const mongoose = require( 'mongoose' ); const app = express() // Database connection mongoose.connect( 'mongodb://127.0.0.1:27017/w3wiki' , { useNewUrlParser: true , useCreateIndex: true , useUnifiedTopology: true }); // User model const User = mongoose.model( 'User' , { name: { type: String }, age: { type: Number } }); var query = User.find(); var area = { center: [10, 10], radius: 50, unique: true } query.where( 'loc' ).within().centerSphere(area) console.log(query._conditions.loc.$geoWithin) app.listen(3000, function (error ) { if (error) console.log(error) console.log( "Server listening on PORT 3000" ) }); |
- The project structure will look like this:
node index.js
Output :
Server listening on PORT 3000 { '$centerSphere': [ [ 10, 10 ], 50 ], '$uniqueDocs': true }
Reference:https://mongoosejs.com/docs/api/query.html#query_Query-centerSphere
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