Why is the data not updated when withdrawing via knex?

Question

Node.js

When outputting to /api, when I add an entry to the database and refresh the page, new data is not displayed. Those. they are output but only on server restart, in php it works without server restart so i'm a bit confused.

// connection DB
const options = {
    client: 'pg',
    connection: {
        host: 'localhost',
        user: 'postgres',
        password: '1',
        database: 'chat'
    }
}
const webpack = require('webpack');
// const webpackDevMiddleware = require('webpack-dev-middleware');
const webpackConfig = require('./webpack.config.js');

const 
    knex = require('knex')(options),
    Koa = require('koa'),
    router = require('koa-router')(),
    http = require('http'),
    app = new Koa(),
    serve = require('koa-static'),
    server = http.createServer(app.callback()),
    io = require('socket.io')(server);

knex.schema.hasTable('messages').then(exists => {
    if (!exists) {
        return knex.schema.createTable('messages', t => {
            t.increments('id').primary();
            t.string('message', 100);
            t.string('idroom', 100);
        });
    }
});

io.on('connection', client => {
    client.join('messages');
    client.on('message', req => {
        insertInto(req);
        io.to('messages').emit('message', req.message);
    });
});

let messages;
knex.select().from('messages').timeout(1000).then(res => {
    messages = JSON.stringify(res);
});

router.get('/api', async (ctx, next) => {
    ctx.body = messages;
});

// add value to database
function insertInto(req){
    req.idroom = 'messages';
    knex.insert([req], ['id']).into('messages')
        .then(() => {
            console.log('result:', { success: true, message: req })
        });
}

app.use(serve(__dirname + '/public'))
    .use(router.routes())
    .use(require('webpack-hot-middleware')(webpack(webpackConfig)))
 
server.listen(process.env.PORT | 3000);
console.log ('Listening at port ' + 3000 + ' ...');

Answer 1

this

let messages;
knex.select().from('messages').timeout(1000).then(res => {
    messages = JSON.stringify(res);
});

works 1 time when the application starts