TypeORM wrong app start.

WrongTypeORMIndex.ts

import * as express from "express";
import ...;
import { createConnection } from "typeorm";
const app = express();

createConnection().then((connection) => {
  app.use(...);
  // Start other middleware and routes...
  app.use(...);
});

app.listen(3000, () => {
  console.log("Server listening in port 3000.");
});