Detailed explanation of basic nodejs operation methods

//连接数据库var mysql = require('mysql');var connection = mysql.createConnection({

    host: 'localhost',

    user: 'root',

    password: 'root',

    database:'carbird'});

connection.connect();//查询connection.query('select * from `think_order`', function(err, rows, fields) {

    if (err) throw err;

    console.log('查询结果为: ', rows);

});//关闭连接connection.end();

var http = require("http");var iconv = require('iconv-lite');var option = {

hostname: "api.api68.com",

path: "/klsf/getLotteryInfo.do?issue=&lotCode=10005"};

var req = http.request(option, function(res) {res.on("data", function(chunk) {console.log(JSON.parse( iconv.decode(chunk, "utf-8") ));

});

}).on("error", function(e) {console.log(e.message);

});

req.end();

{ errorCode: 0,

  message: '操作成功',

  result:

   { businessCode: 0,

     message: '操作成功',

     data:

      { preDrawIssue: 2018030717,

        preDrawCode: '03,13,10,11,01,18,07,12',

        drawIssue: 2018030718,

        drawTime: '2018-03-07 12:01:20',

        preDrawTime: '2018-03-07 11:51:20',

        drawCount: 17,

        firstDragonTiger: 1,

        lastBigSmall: 0,

        sumBigSmall: 1,

        sumNum: 75,

        sumSingleDouble: 0,

        fourthDragonTiger: 0,

        secondDragonTiger: 0,

        thirdDragonTiger: 1,

        frequency: '',

        lotCode: 10005,

        iconUrl: 'http://webapp.1680180.com/images/icon/3x/gdkl@3x.png',

        shelves: 0,

        groupCode: 3,

        lotName: '广东快乐十分',

        totalCount: 84,

        serverTime: '2018-03-07 11:53:50',

        index: 100 } } }

var express = require('express');var app = express();var request = require('request');var cheerio = require('cheerio');

app.get('/', function(req, res) {

  request('http://www.zhongjiantang.com/index.php?c=detail&id=57', function(error, response, body) {

    if (!error && response.statusCode == 200) {

      $ = cheerio.load(body);

      res.json({

          cat: $('h1').text()

      });

    }

  })

});var server = app.listen(3000, function() {

  console.log('listening at 3000');

});

var express = require('express');var app = express();//  主页输出 "Hello World"app.get('/', function (req, res) {

   console.log("主页 GET 请求");

   res.send('Hello GET');

})//  POST 请求app.post('/', function (req, res) {

   console.log("主页 POST 请求");

   res.send('Hello POST');

})//  /del_user 页面响应app.get('/del_user', function (req, res) {

   console.log("/del_user 响应 DELETE 请求");

   res.send('删除页面');

})//  /list_user 页面 GET 请求app.get('/list_user', function (req, res) {

   console.log("/list_user GET 请求");

   res.send('用户列表页面');

})// 对页面 abcd, abxcd, ab123cd, 等响应 GET 请求app.get('/ab*cd', function(req, res) {  

   console.log("/ab*cd GET 请求");

   res.send('正则匹配');

})var server = app.listen(8081, function () {

  var host = server.address().address  var port = server.address().port

  console.log("应用实例，访问地址为 http://%s:%s", host, port)

})

db.select({            table: '数据表',            where: '字段名称='查询条件',

    success: function (result) {

           //查询成功之后相关操作

        }

        ，})

exports.select = function(obj){

    if(!obj){

        log('对象不存在');        return;

    }    if(!obj.hasOwnProperty('field')){

        obj.field ="*";

    }    var Sql = 'SELECT '+obj.field+' FROM '+obj.table ;    if(obj.hasOwnProperty('where')){

        Sql+=' WHERE '+obj.where;

    }    if(obj.hasOwnProperty('limit')){

        Sql+=' LIMIT '+obj.limit;

    }    // console.log(Sql);

    db_query(Sql,obj);

};

function db_query(Sql,obj){

    var db_client=mysql.createClient(config.dbinfo);

    db_client.query(Sql,function(err,data){        if(err){            if(obj.error){                if(obj.hasOwnProperty('error')){

                    obj.error(err);

                }

            }else{

                log('数据库出错：' + err.message);

            }

        }else{            if(obj.hasOwnProperty('success')){

                obj.success(data);

            }

        }        if(obj.hasOwnProperty('callback')){

            obj.callback(err,data);

        }

    });

    db_client.end();

}

var db = require('db'),

//代码示例3//注意还是那个Add，精髓也在这里，随后说到function Add(a, b){

    return a+b;

}//LazyAdd改变了，多了一个参数cbfunction LazyAdd(a, cb){

    return function(b){

        cb(a, b);

    }

}//将Add传给形参cbvar result = LazyAdd(1, Add)// 这个时候去做一些其他的程序，等条件成立之后再去执行result = result(2); // => 3

function requestKj(number) {

    var postData = JSON.stringify(number);    var option = {

        host: 网址,

        path: 地址,

        method: 'POST',

        headers: {            "Content-Type": 'application/json',            "Content-Length": Buffer.byteLength(postData)

        }

    };    var req = http.request(option, function (res) {

        res.on('data', function () {

        });

        res.on('end', function () {

            console.log('成功前端给php');

        });

    });

    req.write(postData);

    req.end();

    setTimeout(function () {

        yuegengxin(number);

    },1000)

}

public function nodejs_get_data(){

    $data= json_decode(file_get_contents('php://input'),true);        //对$data数据的相关操作

}