如何使用Express显示mysql中的图像

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

const connection = mysql.createConnection({
  host: 'localhost',
  user: 'your_username',
  password: 'your_password',
  database: 'your_database'
});

app.get('/images/:id', (req, res) => {
  const imageId = req.params.id;
  
  // 查询数据库获取图像的二进制数据
  const query = 'SELECT image_data FROM images WHERE id = ?';
  connection.query(query, [imageId], (error, results, fields) => {
    if (error) {
      console.log('Error retrieving image from database:', error);
      res.status(500).send('Error retrieving image from database');
    } else {
      if (results.length > 0) {
        const imageData = results[0].image_data;
        
        // 将图像数据发送给客户端
        res.contentType('image/jpeg'); // 设置图像的Content-Type
        res.send(imageData);
      } else {
        res.status(404).send('Image not found');
      }
    }
  });
});

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