API for making query searches not working - node.js

Question

I'm trying to fetch all records from MongoDB starting with the Alphabet S but every time I try doing so, it returns nothing but []. I'm using the Params tab on Postman to do this.
The code that I have written is below as well as a snip from Postman to make the question more understandable. I'm pretty sure that the API I have written to perform this has something wrong with it.
The Model file
const mongoose = require('mongoose');
const entry = new mongoose.Schema({
name : {
type : String,
},
collegeName : {
type : String,
},
location : {
type : String,
}
});
const enter = mongoose.model("Student", entry);
module.exports = enter;
index.js
const express = require('express');
const app = express();
const bodyParser = require('body-parser');
const mongo = require('mongodb');
const dataModel = require('./model/model');
const MongoClient = mongo.MongoClient;
const uri = "mongodb+srv://coolhack069:XzC6N7dOyUeQl8M9#cluster0.kz6v9.mongodb.net/assignment?retryWrites=true&w=majority";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
app.use(express.json());
app.use(bodyParser.json());
const port = 3001;
app.get('/api/get', (req, res) => {
client.connect(err => {
if(err) {
throw err;
}
const collection = client.db('assignment').collection('data');
const fetchedData = {};
collection.find(fetchedData).toArray(function(err, result) {
res.send(result);
client.close();
});
})
});
app.get('/api/getStudentDetails', (req, res) => { //The API I have written to query through the Database
client.connect(err => {
if(err) {
throw err;
}
const collection = client.db('assignment').collection('data');
const fetchedData = new dataModel({
name : req.params.name
});
collection.find(fetchedData).toArray(function(err, result) {
res.send(result);
client.close();
})
})
});
app.post('/api/add', (req, res) => { //To add Data
const name = req.body.name;
const collegeName = req.body.collegeName;
const location = req.body.location;
client.connect(err => {
if(err) {
throw err;
}
const collection = client.db('assignment').collection('data');
const storeData = new dataModel({
name : name,
collegeName : collegeName,
location : location
});
console.log(storeData);
collection.insertOne(storeData, function(err, result) {
res.json({
result : "Success"
});
console.log(err);
client.close();
});
})
});
app.listen(port, () => {
console.log(`Application running at http://localhost:${port}`)
})
The Screenshot from Postman

Answer 1

Your find condition is not correct:
const fetchedData = new dataModel({ // ???
name : req.params.name
});
collection.find(fetchedData).toArray(function(err, result) {
res.send(result);
client.close();
})
??? - I guest your meaning is const fetchedData = { name: req.params.name}; - Find every document which have name is req.params.name (S - in your case). But there is no document has name is S in your collection, then it returns [].
If you want to find the documents with S as the first character of their name, you can use Regex syntax:
const query = {
name : new RegExp('^' + req.params.name, 'i'), // i - case insensitive, => /^S/i
};
collection.find(query).toArray(function(err, result) {
res.send(result);
client.close();
})