藉助node.js + mysql 學習基礎ajax~

風吹一個大耳東發表於2019-02-16
Node.jsMySql

很多小白不知道ajax怎麼學，所以就弄了個node後臺模擬下基本的ajax請求。

環境要求是安裝node~

先上linkMysql.js

var mysql = require(`mysql`)
var connection = mysql.createConnection({
  host: `localhost`,
  user: `root`,
  password: ``, //自己資料庫的密碼
  database: ``//自己資料庫的名稱
})

function LinkMysql(tableName, key, value) {
  connection.connect()
  var data = ``
  var sql = `SELECT * FROM ` + tableName +` where ` + key + `=` + value
  console.log(sql)
  return new Promise(function(resolve,reject) {
    connection.query(sql, function(err, result) {
      console.log(`--------------------------SELECT----------------------------`);
      console.log(result);
      console.log(`------------------------------------------------------------

`);  
      resolve(result)
    })
  })
}

function cutMysql() {
  connection.end();
}

module.exports = {
  cutMysql,
  LinkMysql
}

主JS server.js,提供連線maysql和不連線mysql兩種版本

var http = require(`http`)
var url = require(`url`);
var util = require(`util`);
var sqlFunc = require(`./linkMysql.js`);

// 不連線資料庫操作
// var tempJson = [{
//   name: `巧克力`,
//   price: 10
// },{
//   name: `薯條`,
//   price: 20
// }]

http.createServer(function(req, res) {
  // 跨域處理
  res.setHeader("Access-Control-Allow-Origin", "*"); 
  res.setHeader("Access-Control-Allow-Headers", "X-Requested-With");
  res.setHeader("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
  res.setHeader("X-Powered-By",` 3.2.1`);
  res.setHeader("Content-Type", "application/json");

  var reqUrl = req.url
  var mainPath = reqUrl.split(`?`)[0]
  var reqData = reqUrl.split(`?`)[1].split(`=`)

  if (mainPath == `/test`) {
    sqlFunc.LinkMysql(`goods_info`, reqData[0], JSON.stringify(decodeURIComponent(reqData[1]))).then(function(val) {
      console.log(`從資料庫獲取資料` + val)
      sqlFunc.cutMysql();

      res.writeHead(200, {`content-Type`: `text/plain; charset=utf-8`});
      res.end(JSON.stringify(val));
    })
    // 不連線資料庫操作
    // res.writeHead(200, {`content-Type`: `text/plain; charset=utf-8`});
    // res.end(JSON.stringify(tempJson));
  } else {
    res.writeHead(404, {`content-Type`: `text/plain; charset=utf-8`});
  }
  

}).listen(3000);

console.log(`Server running at http://localhost:3000`);

最後就是前端html頁面了~test.html,用了原生寫法，具體的就不講了百度一大堆~

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>
  <div>資料請求</div>
  <div class="box">

  </div>
  <script>
    var xhr = new XMLHttpRequest()

    xhr.onreadystatechange = function(){
      if (xhr.readyState == 4) {
        if ((xhr.status >= 200 && xhr.status < 300) || xhr.status == 304) {
          console.log(xhr.responseText)
          var data = JSON.parse(xhr.responseText)
          var str = ``
          for(var i = 0; i < data.length; i ++) {
            str += "<div>name: " + data[i].name + "</div><div>price: " + data[i].price + "</div>"
          }
          document.querySelector(`.box`).innerHTML = str
        } else {
          console.log("Request was unsuccessful: " + xhr.status)
        }
      }
    }

    xhr.open(`get`, `http://localhost:3000/test?name=巧克力`, true)
    xhr.send(null)
  </script>
</body>
</html>

命令列輸入
node server.js 啟動服務 重新整理test.html頁面就能拿到資料了~

相關文章