nodejs web开发实例 前后端数据交互 ajax +mysql

server.js

var http = require(‘http’);

var server = http.createServer(function (req, res) {
var body = ‘’;

req.on('data', function(data) {     // 接收客户端发送过来的数据， 也就是 xmlHttp.send(value);
    if(data==resultdata[0])
    {
         body += data;
    }
    
});

req.on('end', function() {
    res.writeHeader(200, {
        'Content-Type': 'text/plain',
        'Access-Control-Allow-Origin': '*'    //解决跨域问题
    });
    res.write("hello:" + body);
   
    res.end();
})

});

server.listen(3000, function () {
console.log(‘server start at localhost:3000’);
});

var mysql = require(‘mysql’);
var connection = mysql.createConnection({
host : ‘localhost’,
user : ‘root’,
password : ‘yqf19980217’,
port: ‘3306’,
database: ‘test’
});
connection.connect();
var resultdata =[] ;
var sql = ‘SELECT * FROM websites’;
connection.query(sql,function (err, result) {
if(err){
console.log(’[SELECT ERROR] - ',err.message);
return;
}
for (var i = result.length - 1; i >= 0; i–) {
resultdata[i] = result[i].name;
}

     console.log('--------------------------SELECT----------------------------');
     console.log(resultdata[0]);
     console.log('------------------------------------------------------------\n\n');

});

connection.end();

index.html

Document 提交

我是返回的数据:

index.js

var test = document.getElementById(‘test’);
var bt = document.getElementById(‘bt’);

bt.onclick = function () {
var value = document.getElementById(‘username’).value;
var xmlHttp = new XMLHttpRequest();
xmlHttp.onreadystatechange=function()
{
if (xmlHttp.readyState4 && xmlHttp.status200)
{
test.innerHTML = xmlHttp.responseText;
}
};

xmlHttp.open('POST', 'http://127.0.0.1:3000/', true); 
xmlHttp.send(value);      //吧input框中的value发送过去

};