Node.js连接MySQL数据库及构造JSON的正确姿势

            var express = require(‘express‘);
var router = express.Router();
var dd_tongji = require(‘../controller/dd_tongji.js‘); //引入自定义模块

/* GET home page. */
router.get(‘/‘, function(req, res) {
  res.render(‘index‘, { title: ‘Express‘ });
});

router.get(‘/data‘, dd_tongji.get_click); //配置RUL，访问http://localhost:3000/data

module.exports = router;

exports.get_click = function(req, res) {
  return res.jsonp({"hello":"world"});
};

            var mysql = require(‘mysql‘),
    settings = require(‘../settings‘);

module.exports.getConnection = function () {
    if ((module.exports.connection) && (module.exports.connection.socket) && (module.exports.connection._socket.readable) && (module.exports.connection._socket.writable)) {
        return module.exports.connection;
    }
    console.log(((module.exports.connection) ? "UNHEALTHY SQL CONNECTION; RE" : "") + "CONNECT TO SQL.");
    var connection = mysql.createConnection({
            host: settings.mysql.host,
            port: settings.mysql.port,
            database: settings.mysql.database,
            user: settings.mysql.user,
            password: settings.mysql.password,
            charset: "utf8"
    });
    connection.connect(function (err) {
            if (err) {
                console.log("SQL CONNECT ERROR: ", err);
            } else {
                console.log("SQL CONNECT SUCCESSFUL.");
            }
    });
    connection.on("close", function(err) {
            console.log("SQL CONNECTION CLOSED.");
    });
    connection.on("error", function(err) {
            console.log("SQL CONNECTION ERROR: ." + err);
    });
    module.exports.connection = connection;
    return module.exports.connection;
};

module.exports.getConnection();

module.exports = {
mysql: {
          host: ‘127.0.0.1‘,
          port: 3306,
          user: ‘user‘,
          password: ‘123456‘,
          database: ‘mydata‘
       }
}

            var connection = database.getConnection();
connection.query(sql, function(err, rows, fields) {
　　...//rows为查询出的数据，可通过rows[i].字段 访问数据
}

            var database = require(‘./database‘)

/* 传入字符串获取间隔的天数 */function DateDiff(sDate1, sDate2){ //sDate1和sDate2是2002-12-18格式var aDate, oDate1, oDate2, iDays
  aDate = sDate1.split("-")
  oDate1 = new Date(aDate[1] + ‘-‘ + aDate[2] + ‘-‘ + aDate[0]) //转换为12-18-2002格式
  aDate = sDate2.split("-")
  oDate2 = new Date(aDate[1] + ‘-‘ + aDate[2] + ‘-‘ + aDate[0])
  iDays = parseInt(Math.abs(oDate1 - oDate2) / 1000 / 60 / 60 /24) //把相差的毫秒数转换为天数
  return iDays
}

/* 根据参数返回日期的字符串 */function GetDateStr(BeginDate, AddDayCount) {
  var begin = Date.parse(BeginDate);
  var dd = new Date(begin);
  dd.setDate(dd.getDate()+AddDayCount);//获取AddDayCount天后的日期var y = dd.getFullYear();
  var m = dd.getMonth()+1;//获取当前月份的日期var d = dd.getDate();
  if(m<10) m = ‘0‘ + m;
  if(d<10) d = ‘0‘ + d;
  return y + "-" + m + "-" + d;
}

exports.get_click = function(req, res) {

  // console.log(DateDiff(req.query.begin, req.query.end));// 构造日期列表var datelist = []
  var BeginDate = req.query.begin;
  var EndDate = req.query.end;
  var DateNum = DateDiff(BeginDate, EndDate) + 1; // 需要查询的日期天数for (var i=0; i<DateNum; i++) {
    time = GetDateStr(BeginDate, i);
    datelist.push(time)
  }

  console.log(datelist);
  console.log(datelist.length);

  // data 用于保存查询到的数据var data = {};
　
  for(var i=0; i< datelist.length; i++) {
    data[datelist[i]] = {
      click_num: 0,
      people_num: 0,
      average_num: 0
    }
  }

  // 定义查询语句var sql = "SELECT * FROM click WHERE genus=‘" + req.query.genus + "‘ AND evt=‘" + req.query.evt + "‘ and date>=‘" + req.query.begin + "‘ and date <=‘" + req.query.end + "‘"
  console.log(sql);

  // 连接数据库var connection = database.getConnection();
  connection.query(sql, function(err, rows, fields) {
    if (err) throw err;

    for(var i=0; i < rows.length; i++) {
      data[rows[i].date] = {
        click_num: rows[i].click_num,
        people_num: rows[i].people_num,
        average: rows[i].average
      }
    }

    var result = {
      genus: req.query.genus,
      evt: req.query.evt,
      data: data
    }

    return res.jsonp(result);
  });
};