统计特定行mysql + express

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

const app = express();

// 创建MySQL连接
const connection = mysql.createConnection({
  host: 'localhost',
  user: 'root',
  password: 'password',
  database: 'database_name'
});

// 连接到MySQL数据库
connection.connect((err) => {
  if (err) {
    console.error('Error connecting to MySQL database: ' + err.stack);
    return;
  }
  console.log('Connected to MySQL database');
});

// 定义路由处理特定行统计请求
app.get('/statistics', (req, res) => {
  const condition = req.query.condition; // 从请求参数中获取条件

  // 构建SQL查询语句
  const sql = `SELECT COUNT(*) AS count FROM table_name WHERE condition = '${condition}'`;

  // 执行查询
  connection.query(sql, (err, results) => {
    if (err) {
      console.error('Error executing MySQL query: ' + err.stack);
      return res.status(500).json({ error: 'Internal Server Error' });
    }

    const count = results[0].count; // 获取统计结果

    // 返回统计结果
    res.json({ count });
  });
});

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