React と PostgreSQL を使用して信頼性の高いデータベース アプリケーションを構築する方法

npx create-react-app database-app

cd database-app

npm install react-router-dom axios pg

const { Pool } = require('pg');

const pool = new Pool({
  user: 'your_username',
  host: 'localhost',
  database: 'your_database',
  password: 'your_password',
  port: 5432,
});

module.exports = pool;

const express = require('express');
const router = express.Router();
const pool = require('../db');

// 创建数据库表
const createTableQuery = `
CREATE TABLE IF NOT EXISTS users (
  id SERIAL PRIMARY KEY,
  name VARCHAR(255),
  email VARCHAR(255)
);
`;

pool.query(createTableQuery, (err, res) => {
  if (err) {
    console.log(err);
  } else {
    console.log('成功创建数据库表');
  }
});

// 获取所有用户
router.get('/users', async (req, res) => {
  try {
    const users = await pool.query('SELECT * FROM users');
    res.json(users.rows);
  } catch (err) {
    console.error(err.message);
    res.status(500).send('Server Error');
  }
});

// 新增用户
router.post('/users', async (req, res) => {
  try {
    const { name, email } = req.body;
    const newUser = await pool.query(
      'INSERT INTO users (name, email) VALUES ($1, $2) RETURNING *',
      [name, email]
    );
    res.json(newUser.rows[0]);
  } catch (err) {
    console.error(err.message);
    res.status(500).send('Server Error');
  }
});

module.exports = router;

import React, { useEffect, useState } from 'react';
import axios from 'axios';

const UserList = () => {
  const [users, setUsers] = useState([]);

  useEffect(() => {
    const fetchUsers = async () => {
      try {
        const response = await axios.get('/api/users');
        setUsers(response.data);
      } catch (error) {
        console.error(error);
      }
    };

    fetchUsers();
  }, []);

  return (
    <div>
      <h1>用户列表</h1>
      {users.map((user) => (
        <div key={user.id}>
          <p>
            姓名: {user.name} 邮箱: {user.email}
          </p>
        </div>
      ))}
    </div>
  );
};

export default UserList;

import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';
import UserList from './components/UserList';

ReactDOM.render(
  <Router>
    <Switch>
      <Route exact path="/" component={UserList} />
    </Switch>
  </Router>,
  document.getElementById('root')
);

npm start