Retrieving data from MongoDB involves using its built-in methods for querying and fetching data. Below is a simple example using Node.js:
First, you’d need to require and connect to MongoDB:
```
const mongodb = require(‘mongodb’);
const MongoClient = mongodb.MongoClient;
const url = “mongodb://localhost:27017/”; // your database url
MongoClient.connect(url, function(err, db) {
if (err) throw err;
const dbo = db.db(“mydb”); // replace “mydb” with your database name
});
```
To fetch all the entries in a collection:
```
dbo.collection(“users”).find({}).toArray(function(err, result) { // replace “users” with your collection name
if (err) throw err;
console.log(result);
db.close();
});
```
To find specific data, you’d pass a query object:
```
let query = { age: 20 }; // replace with your query
dbo.collection(“users”).find(query).toArray(function(err, result) {
if (err) throw err;
console.log(result);
db.close();
});
```
Similarly, to find records where the “name” starts with the letter A
```
let query = { name: /^A/ };
dbo.collection(“users”).find(query).toArray(function(err, result) {
if (err) throw err;
console.log(result);
db.close();
});
```
Data retrieval from MongoDB will depend on your specific requirements, such as the database setup, the collection structure, and the node.js version being used.
