db is not defined

Dear Sir or Madam!

I have a question. I have run the following code in Visual Studio in an environment of react.js. It is the db server. I have a client server that is running the form. If I run this code, the server drop this error:

ReferenceError: db is not defined at C:\node\SAMPLE-CRUD\server\index.js:31:2 at Layer.handle [as handle_request] (C:\node\SAMPLE-CRUD\server\node_modules\express\lib\router\layer.js:95:5) at next (C:\node\SAMPLE-CRUD\server\node_modules\express\lib\router\route.js:144:13) at Route.dispatch (C:\node\SAMPLE-CRUD\server\node_modules\express\lib\router\route.js:114:3) at Layer.handle [as handle_request] (C:\node\SAMPLE-CRUD\server\node_modules\express\lib\router\layer.js:95:5) at C:\node\SAMPLE-CRUD\server\node_modules\express\lib\router\index.js:284:15 at Function.process_params (C:\node\SAMPLE-CRUD\server\node_modules\express\lib\router\index.js:346:12) at next (C:\node\SAMPLE-CRUD\server\node_modules\express\lib\router\index.js:280:10) at C:\node\SAMPLE-CRUD\server\node_modules\body-parser\lib\read.js:137:5 at AsyncResource.runInAsyncScope (node:async_hooks:203:9)

Suppose I turn on this row. I have no mistake but the get request has not functioned. db=await pool.getConnection();

What is the problem? Thank you for your help

This is my server code: const express = require('express'); const app = express(); const PORT = 3001; const mariadb = require('mariadb'); const cors = require('cors');

app.use(cors()); app.use(express.json());

async function asyncFunction() {

const pool = mariadb.createPool({ host:"127.0.0.1", user:"molnarpe", password:"Ildiko1968", database:"employeesystem", connectionLimit: 10, port: 3307 });

app.post('/create', async (req, res) => { const name = req.body.name; const age = req.body.age; const country = req.body.country; const position = req.body.position; const wage = req.body.wage;

db=await pool.getConnection(); db.query("INSERT INTO employees (name, age, country, position, wage) VALUES (?, ?, ?, ?, ?)", [name, age, country, position, wage], (err,result) => { if (err) { console.log(err) } else { res.send("Values inserted") } } ) })

app.get("/employees", (req, res) =>{

pool.getConnection(); db.query("SELECT * FROM employees", (err, result) => { if (err) { console.log(err); } else { res.send(result); } }) })

app.listen(3001, () => { console.log("Server is running on port 3001"); });

module.exports = pool;