node.js如何读取MySQL数据

Posted 2020-09-20 清明-心若淡定

先安装mysql模块。

node.js默认安装时，模块文件放在 /usr/local/lib/node_modules 这个目录下，为了便宜管理，模块还是统一安装到这里好。

$ cd /usr/local/lib         
$ npm install mysql         

程序文件mysql.js

var Client = require(‘/usr/local/lib/node_modules/mysql‘).Client;
var client = new Client();

client.user = ‘root‘;
client.password = ‘‘;

console.log(‘Connecting to MySQL...‘);

client.query(‘USE tiny_shop‘);     //如果MySQL中没有库表，赶紧建。

http = require("http");

var server = http.createServer(function(request, response) {
    response.writeHeader(200, {"Content-Type": "text/html"});

    client.query(‘SELECT * FROM tags‘, function selectCb(err, results, fields) {  
        if (err) {  
            throw err;  
        }  

        var data = ‘‘;
        for (var i=0; i<results.length; i++) {          
            var firstResult = results[i];
            data += ‘id: ‘ + firstResult[‘id‘]+‘tag: ‘ + firstResult[‘tag‘]; 
        } 

        response.write(data); 
        response.end();
    });
});

server.listen(8080);

var sys = require("util");
sys.puts("Server running at http://localhost:8080/"); 

运行

$ node mysql.js

在浏览器里，输入 http://localhost:8080 ，就能显示数据库里的数据了。