通过node-mysql搭建Windows+Node.js+MySQL环境的教程_node.js

前言

MySQL是一款常用的开源数据库产品,通常也是免费数据库的首选。查了一下NPM列表,发现Nodejs有13库可以访问MySQL,felixge/node-mysql似乎是最受关注项目,我也决定尝试用一下。

要注意名字,”felixge/node-mysql”非”node-mysql”,安装部分会介绍这个小插曲!

目录

  • node-mysql介绍
  • 建立MySQL测试库
  • node-mysql安装
  • node-mysql使用

1. node-mysql介绍

felixge/node-mysql是一个纯nodejs的用javascript实现的一个MySQL客户端程序。felixge/node-mysql封装了Nodejs对MySQL的基本操作,100% MIT公共许可证。

项目地址:https://github.com/felixge/node-mysql

2. 建立MySQL测试库

本地创建MySQL测试库:nodejs

~ mysql -uroot -p
mysql> CREATE DATABASE nodejs;
mysql> SHOW DATABASES;
+--------------------+
| Database      |
+--------------------+
| information_schema |
| mysql       |
| nodejs       |
| performance_schema |
+--------------------+
4 rows in set (0.00 sec)

mysql> GRANT ALL ON nodejs.* to nodejs@'%' IDENTIFIED BY 'nodejs';
mysql> GRANT ALL ON nodejs.* to nodejs@localhost IDENTIFIED BY 'nodejs';

重新登陆MySQL

C:\Users\Administrator>mysql -unodejs -p
Enter password: ******

mysql> SHOW DATABASES;
+--------------------+
| Database      |
+--------------------+
| information_schema |
| nodejs       |
| test        |
+--------------------+
3 rows in set (0.00 sec)


mysql> USE nodejs
Database changed

新建一个user表

CREATE TABLE t_user(
id INT PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(16) NOT NULL ,
create_date TIMESTAMP NULL DEFAULT now()
)ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE UNIQUE INDEX t_quiz_IDX_0 on t_user(name);


mysql> SHOW TABLES;
+------------------+
| Tables_in_nodejs |
+------------------+
| t_user      |
+------------------+
1 row in set (0.04 sec)

3. node-mysql安装

我的系统环境

win7 64bit
Nodejs:v0.10.5
Npm:1.2.19
MySQL:Server version: 5.6.11 MySQL Community Server (GPL)
创建工程:nodejs-node-mysql

~ D:\workspace\javascript>mkdir nodejs-node-mysql
~ D:\workspace\javascript>cd nodejs-node-mysql
~ D:\workspace\javascript\nodejs-node-mysql>npm install node-mysql
node-mysql@0.2.0 node_modules\node-mysql
├── better-js-class@0.1.2
├── cps@0.1.7
├── underscore@1.5.2
└── mysql@2.0.0-alpha9 (require-all@0.0.3, bignumber.js@1.0.1)

这里有一个小插曲

安装“node-mysql”后,打开package.json文件发现,这个项目地址是

https://github.com/redblaze/node-mysql.git
从依赖关系可以看到,它依赖于mysql库,是对felixge/node-mysql的封装。

node-mysql1

由于这个项目star是0,fork也是0. 所以,我也不准备花时间测试了,重新安装felixge/node-mysql的包。

重新安装node-mysql

~ D:\workspace\javascript\nodejs-node-mysql>rm -rf node_modules
~ D:\workspace\javascript\nodejs-node-mysql>npm install mysql@2.0.0-alpha9
npm http GET https://registry.npmjs.org/mysql/2.0.0-alpha9
npm http 200 https://registry.npmjs.org/mysql/2.0.0-alpha9
npm http GET https://registry.npmjs.org/mysql/-/mysql-2.0.0-alpha9.tgz
npm http 200 https://registry.npmjs.org/mysql/-/mysql-2.0.0-alpha9.tgz
npm http GET https://registry.npmjs.org/require-all/0.0.3
npm http GET https://registry.npmjs.org/bignumber.js/1.0.1
npm http 304 https://registry.npmjs.org/require-all/0.0.3
npm http 304 https://registry.npmjs.org/bignumber.js/1.0.1
mysql@2.0.0-alpha9 node_modules\mysql
├── require-all@0.0.3
└── bignumber.js@1.0.1

这回就对了,继续下面的开发!

创建node程序启动文件:app.js

第一个测试

~ vi app.js
var mysql = require('mysql');
var conn = mysql.createConnection({
  host: 'localhost',
  user: 'nodejs',
  password: 'nodejs',
  database:'nodejs',
  port: 3306
});
conn.connect();
conn.query('SELECT 1 + 1 AS solution', function(err, rows, fields) {
  if (err) throw err;
  console.log('The solution is: ', rows[0].solution);
});
conn.end();

运行node

~ D:\workspace\javascript\nodejs-node-mysql>node app.js
The solution is: 2

这样我们就让Nodejs连接上了MySQL。

4. node-mysql使用

下面我们要对node-mysql的API进行常用的测试。

表新删改查
连接池配置
MySQL断线重连
连接池超时测试
1). 表新删改查
修改app.js

~ vi app.js
var mysql = require('mysql');
var conn = mysql.createConnection({
  host: 'localhost',
  user: 'nodejs',
  password: 'nodejs',
  database: 'nodejs',
  port: 3306
});
conn.connect();

var insertSQL = 'insert into t_user(name) values("conan"),("fens.me")';
var selectSQL = 'select * from t_user limit 10';
var deleteSQL = 'delete from t_user';
var updateSQL = 'update t_user set name="conan update" where name="conan"';

//delete
conn.query(deleteSQL, function (err0, res0) {
  if (err0) console.log(err0);
  console.log("DELETE Return ==> ");
  console.log(res0);

  //insert
  conn.query(insertSQL, function (err1, res1) {
    if (err1) console.log(err1);
    console.log("INSERT Return ==> ");
    console.log(res1);

    //query
    conn.query(selectSQL, function (err2, rows) {
      if (err2) console.log(err2);

      console.log("SELECT ==> ");
      for (var i in rows) {
        console.log(rows[i]);
      }

      //update
      conn.query(updateSQL, function (err3, res3) {
        if (err3) console.log(err3);
        console.log("UPDATE Return ==> ");
        console.log(res3);

        //query
        conn.query(selectSQL, function (err4, rows2) {
          if (err4) console.log(err4);

          console.log("SELECT ==> ");
          for (var i in rows2) {
            console.log(rows2[i]);
          }
        });
      });
    });
  });
});

//conn.end();

控制台输出:

D:\workspace\javascript\nodejs-node-mysql>node app.js
DELETE Return ==>
{ fieldCount: 0,
 affectedRows: 2,
 insertId: 0,
 serverStatus: 34,
 warningCount: 0,
 message: '',
 protocol41: true,
 changedRows: 0 }
INSERT Return ==>
{ fieldCount: 0,
 affectedRows: 2,
 insertId: 33,
 serverStatus: 2,
 warningCount: 0,
 message: '&Records: 2 Duplicates: 0 Warnings: 0',
 protocol41: true,
 changedRows: 0 }
SELECT ==>
{ id: 33,
 name: 'conan',
 create_date: Wed Sep 11 2013 12:09:15 GMT+0800 (中国标准时间) }
{ id: 34,
 name: 'fens.me',
 create_date: Wed Sep 11 2013 12:09:15 GMT+0800 (中国标准时间) }
UPDATE Return ==>
{ fieldCount: 0,
 affectedRows: 1,
 insertId: 0,
 serverStatus: 2,
 warningCount: 0,
 message: '(Rows matched: 1 Changed: 1 Warnings: 0',
 protocol41: true,
 changedRows: 1 }
SELECT ==>
{ id: 33,
 name: 'conan update',
 create_date: Wed Sep 11 2013 12:09:15 GMT+0800 (中国标准时间) }
{ id: 34,
 name: 'fens.me',
 create_date: Wed Sep 11 2013 12:09:15 GMT+0800 (中国标准时间) }

由于node的异步的,上面是一个连续的操作,代码会被写的支离破碎。我们可以通过async库对上面代码进行封装,请参考文章:Nodejs异步流程控制Async

2). 连接池配置

增加文件:app-pooling.js

~ vi app-pooling.js

var mysql = require('mysql');
var pool = mysql.createPool({
  host: 'localhost',
  user: 'nodejs',
  password: 'nodejs',
  database: 'nodejs',
  port: 3306
});

var selectSQL = 'select * from t_user limit 10';

pool.getConnection(function (err, conn) {
  if (err) console.log("POOL ==> " + err);

  conn.query(selectSQL,function(err,rows){
    if (err) console.log(err);
    console.log("SELECT ==> ");
    for (var i in rows) {
      console.log(rows[i]);
    }
    conn.release();
  });
});

控制台输出:

D:\workspace\javascript\nodejs-node-mysql>node app-pooling.js
SELECT ==>
{ id: 39,
 name: 'conan update',
 create_date: Wed Sep 11 2013 13:41:18 GMT+0800 (中国标准时间) }
{ id: 40,
 name: 'fens.me',
 create_date: Wed Sep 11 2013 13:41:18 GMT+0800 (中国标准时间) }

3). MySQL断线重连

分别模拟3种错误

a.登陆密码错误
b.数据库宕机
c.数据库连接超时
新增文件:app-reconnect.js

~ vi app-reconnect.js

var mysql = require('mysql');
var conn;
function handleError () {
  conn = mysql.createConnection({
    host: 'localhost',
    user: 'nodejs',
    password: 'nodejs',
    database: 'nodejs',
    port: 3306
  });

  //连接错误,2秒重试
  conn.connect(function (err) {
    if (err) {
      console.log('error when connecting to db:', err);
      setTimeout(handleError , 2000);
    }
  });

  conn.on('error', function (err) {
    console.log('db error', err);
    // 如果是连接断开,自动重新连接
    if (err.code === 'PROTOCOL_CONNECTION_LOST') {
      handleError();
    } else {
      throw err;
    }
  });
}
handleError();

a. 模拟密码错误

修改password: ‘nodejs11'

控制台输出。

D:\workspace\javascript\nodejs-node-mysql>node app-reconnect.js
error when connecting to db: { [Error: ER_ACCESS_DENIED_ERROR: Access denied for user 'nodejs'@'localhost' (using pass
rd: YES)]
 code: 'ER_ACCESS_DENIED_ERROR',
 errno: 1045,
 sqlState: '28000',
 fatal: true }
error when connecting to db: { [Error: ER_ACCESS_DENIED_ERROR: Access denied for user 'nodejs'@'localhost' (using pass
rd: YES)]
 code: 'ER_ACCESS_DENIED_ERROR',
 errno: 1045,
 sqlState: '28000',
 fatal: true }

b. 模拟数据库宕机
正常启动node,然后杀掉mysqld的进程。

控制台输出。


D:\workspace\javascript\nodejs-node-mysql>node app-reconnect.js
db error { [Error: read ECONNRESET]
 code: 'ECONNRESET',
 errno: 'ECONNRESET',
 syscall: 'read',
 fatal: true }

Error: read ECONNRESET
  at errnoException (net.js:884:11)
  at TCP.onread (net.js:539:19)

这个异常,直接导致node程序被杀死!

c. 模拟连接超时,PROTOCOL_CONNECTION_LOST
切换到root账户, 修改MySQL的wait_timeout参数,设置为10毫秒超时。

~ mysql -uroot -p
mysql> show variables like 'wait_timeout';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wait_timeout | 28800 |
+---------------+-------+
1 row in set (0.00 sec)

mysql> set global wait_timeout=10;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like 'wait_timeout';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wait_timeout | 10  |
+---------------+-------+
1 row in set (0.00 sec)

修改文件:app-reconnection.js,在最后增加代码

~ vi app-reconnection.js

function query(){
  console.log(new Date());
  var sql = "show variables like 'wait_timeout'";
  conn.query(sql, function (err, res) {
    console.log(res);
  });
}

query();
setInterval(query, 15*1000);

程序会每融15秒,做一次查询。

控制台输出

D:\workspace\javascript\nodejs-node-mysql>node app-reconnect.js
Wed Sep 11 2013 15:21:14 GMT+0800 (中国标准时间)
[ { Variable_name: 'wait_timeout', Value: '10' } ]
db error { [Error: Connection lost: The server closed the connection.] fatal: true, code: 'PROTOCOL_CONNECTION_LOST' }
Wed Sep 11 2013 15:21:28 GMT+0800 (中国标准时间)
[ { Variable_name: 'wait_timeout', Value: '10' } ]
db error { [Error: Connection lost: The server closed the connection.] fatal: true, code: 'PROTOCOL_CONNECTION_LOST' }
Wed Sep 11 2013 15:21:43 GMT+0800 (中国标准时间)
[ { Variable_name: 'wait_timeout', Value: '10' } ]

我们自己的程序捕获了“PROTOCOL_CONNECTION_LOST”异常,并自动的实现了数据库重连。

4). MySQL连接池的超时测试

针对wait_timeout问题,我们再对连接做一下测试。

修改app-pooling.js文件

var mysql = require('mysql');
var pool = mysql.createPool({
  host: 'localhost',
  user: 'nodejs',
  password: 'nodejs',
  database: 'nodejs',
  port: 3306
});

var selectSQL ="show variables like 'wait_timeout'";

pool.getConnection(function (err, conn) {
  if (err) console.log("POOL ==> " + err);

  function query(){
    conn.query(selectSQL, function (err, res) {
      console.log(new Date());
      console.log(res);
      conn.release();
    });
  }
  query();
  setInterval(query, 5000);
});

控制台输出:

D:\workspace\javascript\nodejs-node-mysql>node app-pooling.js
Wed Sep 11 2013 15:32:25 GMT+0800 (中国标准时间)
[ { Variable_name: 'wait_timeout', Value: '10' } ]
Wed Sep 11 2013 15:32:30 GMT+0800 (中国标准时间)
[ { Variable_name: 'wait_timeout', Value: '10' } ]
Wed Sep 11 2013 15:32:35 GMT+0800 (中国标准时间)
[ { Variable_name: 'wait_timeout', Value: '10' } ]

连接池,已经解决了自动重连的问题了,后面我们的开发,可以尽量使用pooling的方式。