簡單示例:NodeJs鏈接mysql數據庫

開篇引用網上的說法：

簡單的說 Node.js 就是運行在服務端的 JavaScript。Node.js 是一個基於Chrome JavaScript 運行時創建的一個平臺。Node.js是一個事件驅動I/O服務端JavaScript環境，基於Google的V8引擎，V8引擎執行Javascript的速度很是快，性能很是好。

關於常見的五種I/O模型，你們能夠自行搜索瞭解。

下面的示例，是基於NodeJS+express而作的。

NodeJs環境的安裝在此不作陳述。下面假設你已經安裝了NodeJS環境。而後經過

npm install  express --save

示例代碼以下：

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



app.get('/getCode',function(req,res){
	
var connection = mysql.createConnection({
  host     : 'localhost',
  user     : 'root',
  password : '******',
  database : 'codedb'
});
connection.connect();
connection.query('SELECT * from sfk_acm_code', function (error, results, fields) 
{
  if (error) throw error;
  for(var i in results)
  {
  console.log('The solution is: ', results[i]['code']);
  }
  res.send(results);
});
	connection.end();
});
var server = app.listen(8080, function () {
 
  var host = server.address().address
  var port = server.address().port
 
  console.log("應用實例，訪問地址爲 http://%s:%s", host, port)
 
})

執行命令：

node mysql.js

注意：要定位到mysql.js所在的目錄，而後執行node命裏。

訪問：http://127.0.0.1:8080/getCode，結果以下：

[{"id":2,"code":"一級建造師\nXXXXX-XXXXXXXXX-XX","subject_id":6,"state":1,"created_by":"admin","created_on":"2019-02-19T06:42:13.035Z","modify_by":"admin","modify_on":"2019-02-23T08:41:58.495Z","del":0},{"id":3,"code":"一級建造師\nXXXXX-XXXXXXXXX-XX\n二級建造師\nABCIEF890-XUIWEJF-CFDIFQW","subject_id":6,"state":0,"created_by":"admin","created_on":"2019-02-19T06:42:45.511Z","modify_by":"admin","modify_on":"2019-02-19T08:11:02.018Z","del":1},{"id":4,"code":"造價工程師歷年真題\nXXXXX-XXXXXXXXX-XXXXX\n消防工程師\nXXXXX-XXXXXXXXXX-XXXXX","subject_id":6,"state":1,"created_by":"admin","created_on":"2019-02-19T08:04:22.776Z","modify_by":"admin","modify_on":"2019-02-23T08:42:27.897Z","del":0},{"id":5,"code":"註冊消防工程師\nXXXXXXXXXXXX-XXXXXXXX-XXXXXXX","subject_id":5,"state":1,"created_by":"admin","created_on":"2019-02-19T08:59:15.200Z","modify_by":"admin","modify_on":"2019-02-23T08:52:46.093Z","del":0},{"id":6,"code":"一級建造師\nXXXX-XXX-XXDDCV\n二級建造師\nDFEF-UIDF-XIKFNW","subject_id":6,"state":0,"created_by":"admin","created_on":"2019-02-20T09:58:55.852Z","modify_by":"/Demand/Recycle","modify_on":"2019-02-23T09:07:01.074Z","del":0},{"id":7,"code":"一級建造師建設工程項目管理\n    5NKOX-5T1P2-N345J-FNUPM\n","subject_id":10,"state":1,"created_by":"admin","created_on":"2019-02-21T09:14:09.855Z","modify_by":"admin","modify_on":"2019-02-23T08:54:25.170Z","del":0},{"id":8,"code":"\n一級建造師建築工程管理與實務\n    7CSVK-0H5CK-HOYGW-M3MS0","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-21T09:14:36.335Z","modify_by":"/Demand/Recycle","modify_on":"2019-02-23T06:17:57.914Z","del":0},{"id":9,"code":"vcxv","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T05:50:09.948Z","modify_by":"admin","modify_on":"2019-02-26T05:50:09.948Z","del":0},{"id":10,"code":"cccvxc","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T05:50:39.086Z","modify_by":"admin","modify_on":"2019-02-26T05:50:39.086Z","del":0},{"id":11,"code":"fdsf","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T05:51:45.386Z","modify_by":"admin","modify_on":"2019-02-26T05:51:45.386Z","del":0},{"id":12,"code":"dfds","subject_id":10,"state":0,"created_by":"admin","created_on":"2019-02-26T05:52:19.586Z","modify_by":"admin","modify_on":"2019-02-26T05:52:19.586Z","del":0},{"id":13,"code":"dfsf","subject_id":10,"state":0,"created_by":"admin","created_on":"2019-02-26T05:53:12.713Z","modify_by":"admin","modify_on":"2019-02-26T05:53:12.713Z","del":0},{"id":14,"code":"dfdsf","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T05:54:34.497Z","modify_by":"admin","modify_on":"2019-02-26T05:54:34.497Z","del":0},{"id":15,"code":"fdsfads","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T05:55:22.131Z","modify_by":"admin","modify_on":"2019-02-26T05:55:22.131Z","del":0},{"id":16,"code":"fdefasdf","subject_id":10,"state":0,"created_by":"admin","created_on":"2019-02-26T05:55:35.520Z","modify_by":"admin","modify_on":"2019-02-26T05:55:35.520Z","del":0},{"id":17,"code":"fdsfds","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T05:56:01.081Z","modify_by":"admin","modify_on":"2019-02-26T05:56:01.081Z","del":0},{"id":18,"code":"fdsfsd","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T05:57:05.578Z","modify_by":"admin","modify_on":"2019-02-26T05:57:05.578Z","del":0},{"id":19,"code":"fdsf","subject_id":10,"state":0,"created_by":"admin","created_on":"2019-02-26T05:57:27.338Z","modify_by":"admin","modify_on":"2019-02-26T05:57:27.338Z","del":0},{"id":20,"code":"dd","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T05:58:15.470Z","modify_by":"admin","modify_on":"2019-02-26T05:58:15.470Z","del":0},{"id":21,"code":"fsdfs","subject_id":10,"state":0,"created_by":"admin","created_on":"2019-02-26T05:58:54.686Z","modify_by":"admin","modify_on":"2019-02-26T05:58:54.686Z","del":0},{"id":22,"code":"fdsfds","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T06:00:28.632Z","modify_by":"admin","modify_on":"2019-02-26T06:00:28.632Z","del":0},{"id":23,"code":"fsdfsd","subject_id":12,"state":0,"created_by":"admin","created_on":"2019-02-26T06:00:40.941Z","modify_by":"admin","modify_on":"2019-02-26T06:00:40.941Z","del":0},{"id":24,"code":"fdsafsdaf","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T06:01:32.405Z","modify_by":"admin","modify_on":"2019-02-26T06:01:32.405Z","del":0},{"id":25,"code":"34rsdfsdaf","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T06:01:36.674Z","modify_by":"admin","modify_on":"2019-02-26T06:01:36.674Z","del":0},{"id":26,"code":"fdsafsdfd","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T06:01:40.462Z","modify_by":"admin","modify_on":"2019-02-26T06:01:40.462Z","del":0},{"id":27,"code":"fdsfsdf","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T06:01:43.470Z","modify_by":"admin","modify_on":"2019-02-26T06:01:43.470Z","del":0},{"id":28,"code":"fdsfds","subject_id":11,"state":0,"created_by":"admin","created_on":"2019-02-26T06:02:21.008Z","modify_by":"admin","modify_on":"2019-02-26T06:02:21.008Z","del":0}]