1.背景：

node.js是一款流行的运行在服务端的 JavaScript，使用JavaScript语言进行编程，快速实现一些简单web服务等功能。

2.连接GBase代码示例：

使用node.js前先进行环境安装，化简安装步骤如下：

#先从node.js网站上下载node.js安装包，本例中安装包为，也可以从https://nodejs.org/zh-cn/download/prebuilt-binaries地址上手动下载
wget https://nodejs.org/dist/v22.11.0/node-v22.11.0-linux-x64.tar.xz    // 下载
tar -xvf  node-v10.9.0-linux-x64.tar.xz       // 解压
cd node-v10.9.0-linux-x64/                  // 进入解压目录
./bin/node -v                               // 执行node命令 查看版本

#解压文件的 bin 目录底下包含了 node、npm 等命令，我们可以使用 ln 命令来设置软连接：
ln -s /usr/software/nodejs/bin/npm   /usr/local/bin/ 
ln -s /usr/software/nodejs/bin/node   /usr/local/bin/

以下为一段node.js连接gbase8a的代码示例，注意由于目前8a还么有javascript的连接驱动程序，因此需要使用mysql的连接驱动package来进行连接，本例中使用了express和mysql这两个package，需要提前进行安装，具体安装指令示例如下：

#创建代码目录：
mkdir test
cd test
npm install express --save //下载方式安装express package
npm install mysql --save   //下载方式安装mysql package
#完成后会在创建的test目录下生成node_modules目录内部包括下载的全部package和其依赖package，并生成package.json，package-lock.json两个文件作为下载package的描述信息

以下为连接gbase8a进行简单查询的示例代码：

其中gbase8a中的test.t1表结构如下：

CREATE TABLE "t1" (
  "a" int(11) DEFAULT NULL,
  "b" int(11) DEFAULT NULL,
  "c" int(11) DEFAULT NULL
) ENGINE=EXPRESS DEFAULT CHARSET=utf8 TABLESPACE='sys_tablespace'

具体node.js代码test.js文件内容如下：

const express = require('express');
const mysql = require('mysql');
const util = require('util');
const bodyParser = require('body-parser');

// Promisify the mysql query method for a given connection
const promisifyQuery = (connection) => {
  const query = util.promisify(connection.query).bind(connection);
  return query;
};

const app = express();
const myport = 3000;

app.use(bodyParser.json());

app.post('/connect', async (req, res) => {
  const { host, user, password, database, port } = req.body;

  if (!host || !user || !password || !database || !port) {
    return res.status(400).json({ error: 'Missing required connection parameters' });
  }

  const connectionConfig = {
    host: host,
    user: user,
    password: password,
    database: database,
    port: port
  };


  let connection;

  try {
    connection = mysql.createConnection(connectionConfig);

    // Execute the SQL query
    connection.query('SELECT a, b, c FROM t1 limit 10', function (error, results, fields) {
      if(error){
          console.log('[SELECT ERROR] - ',error.message);
          return;
       }

       console.log('--------------------------SELECT----------------------------');
       console.log(results);
       console.log('------------------------------------------------------------\n\n');
       res.json({results});
    });
  } catch (error) {
    // Handle database connection or query errors
    console.error('Database error:', error);
    res.status(500).json({ error: 'Database connection or query failed', message: error.message });
  } finally {
    // Ensure the database connection is closed
    if (connection) {
      connection.end();
    }
  }
});

app.listen(myport, () => {
  console.log(`Server is running on http://localhost:${myport}`);
});

3.调用和执行效果：

运行test.js javascript

[gbase@kylin10danji test]$ node test1.js
Server is running on http://localhost:3000

使用curl工具发送post请求给服务端口：

[gbase@kylin10danji gbase]$ curl -X POST http://localhost:3000/connect -H "Content-Type: application/json" -d '{"host":"192.168.56.161","user":"gbase","password":"gbase20110531","database":"test","port":"5258"}'

test.js服务端打屏显示：

[gbase@kylin10danji test]$ node test1.js
Server is running on http://localhost:3000
--------------------------SELECT----------------------------
[
  RowDataPacket { a: 1, b: 2, c: 3 },
  RowDataPacket { a: 1, b: 3, c: 6 },
  RowDataPacket { a: 1, b: 5, c: 6 },
  RowDataPacket { a: 2, b: 2, c: 3 },
  RowDataPacket { a: 2, b: 3, c: 6 },
  RowDataPacket { a: 2, b: 5, c: 6 },
  RowDataPacket { a: 1, b: 2, c: 3 },
  RowDataPacket { a: 1, b: 3, c: 6 },
  RowDataPacket { a: 1, b: 5, c: 6 },
  RowDataPacket { a: 2, b: 2, c: 3 }
]
------------------------------------------------------------

返回curl客户端信息：

[gbase@kylin10danji gbase]$ curl -X POST http://localhost:3000/connect -H "Content-Type: application/json" -d '{"host":"192.168.56.161","user":"gbase","password":"gbase20110531","database":"test","port":"5258"}'
{"results":[{"a":1,"b":2,"c":3},{"a":1,"b":3,"c":6},{"a":1,"b":5,"c":6},{"a":2,"b":2,"c":3},{"a":2,"b":3,"c":6},{"a":2,"b":5,"c":6},{"a":1,"b":2,"c":3},{"a":1,"b":3,"c":6},{"a":1,"b":5,"c":6},{"a":2,"b":2,"c":3}]}