Node.js连接数据库前，需要安装相应的包，如果安装sql server 需要先装包node-sqlserver。我们以mysql为案例来说明node.js查询mysql数据。

1、安装 node-mysql

npm install node-mysql

2、通过express框架实现数据库连接

var express = require('express');
var mysql = require('mysql');
var app = express();
app.use(function(req, res, next){
  console.log('%s %s', req.method, req.url);
  next();
});
var conn = mysql.createConnection({
    host:'localhost',
    user:'root',
    database:'ceshi',
    password:'123456',
    port:3306
});
conn.connect();
app.get('/', function(req, res){
   conn.query('SELECT * from ceshibiao', function(err, rows, fields) {
        if(err) throw err;
        var data = http://www.mamicode.com/'';>
Node.js连接数据库