Angular html表单-下拉列表未在MySql数据库中填充值

CREATE TABLE options (
  id INT PRIMARY KEY,
  value VARCHAR(255)
);

const express = require('express');
const mysql = require('mysql');

const app = express();
const connection = mysql.createConnection({
  host: 'localhost',
  user: 'username',
  password: 'password',
  database: 'database_name'
});

app.get('/options', (req, res) => {
  connection.query('SELECT * FROM options', (error, results) => {
    if (error) throw error;
    res.json(results);
  });
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

import { Component, OnInit } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-dropdown',
  template: `
    <select>
      <option *ngFor="let option of options" [value]="option.id">{{ option.value }}</option>
    </select>
  `
})
export class DropdownComponent implements OnInit {
  options: any[];

  constructor(private http: HttpClient) {}

  ngOnInit() {
    this.http.get<any[]>('/options').subscribe(data => {
      this.options = data;
    });
  }
}