当前位置：网站首页>Nodejs + Mysql realize simple registration function (small demo)

Nodejs + Mysql realize simple registration function (small demo)

2022-04-23 13:06:00 【It's never too late to be alone】

  1. Create a database and create data tables , Pictured ：
    The database name is expressdb, Table, user
    2. Create two fields ,uuid Field is used to receive passwords ,userName Field is used to receive the name , Pictured ：
    Insert picture description here
    3.nodejs The code is as follows , After operation ：
// Express  It's a simple and flexible one  node.js Web Application framework ,  Provides a series of powerful features to help you create a variety of  Web  application , And the rich  HTTP  Tools .
var express = require('express');
var mysql = require('mysql');
var app = express();
var bodyParser = require('body-parser');

var urlencodedParser = bodyParser.urlencoded({ extended: false });//  establish  application/x-www-form-urlencoded  Code parsing 
//  Configure and modify the database user name 、 And password and database name 
var connection = mysql.createConnection({
    host     : 'localhost',       
    user     : 'root',              
    password : 'root',       
    port: '3306',                   
    database: 'expressdb' 
});
connection.connect();

//  Solve cross domain access 
app.all('/',function(req,res,next){
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST');
    res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type, Authorization');
    next();
});

app.post('/',urlencodedParser,function(req,res){
    // console.log(req);
    var name = req.body.name;
    var password = req.body.password;
    var data = [password,name];
    var _res = res;
    var sql_add = 'INSERT INTO user(uuid,userName) VALUES(?,?)';// Add data 
    var sql_select = 'SELECT * FROM user';// Query data 
    connection.query(sql_select,function(err,result){
        if(err){
            _res.send(err.message);
            return;
        }else{
            var ta = true;
            result.forEach(item => {
                if(item.uuid == password && item.userName == name){
                    _res.send(' Your account has been registered , Clear re registration ！');
                    ta = false;
                    return;
                }
            });
            if(ta){
                connection.query(sql_add,data,function(err,result){
                    if(err){
                     _res.send(err.message);
                      return;
                    }
                    _res.send(' Registered successfully ;');
                 })
            }
        }
       
    })
    // res.end(' The request is successful ');

});
var server = app.listen(3000,function(){
    var host = server.address().address
    var port = server.address().port
    console.log(' Successfully monitored ',host,port);
});

4. The front-end request code is as follows ：

	<body>
		<ul>
			<li class="list">
				<span class="name"> full name ：</span>
				<input type="" name="name" id="name" value="" />
			</li>
			<li class="list">
				<span class="password"> password ：</span>
				<input type="" name="password" id="password" value="" />
			</li>
			<button class="but" onclick="register()"> register </button>
		</ul>
	</body>

<script type="text/javascript">
	function register() {
    
        var name = $('#name').val();
        var passwords = $('#password').val();
        ajax(name,passwords);
	}
	function ajax(name,passwords) {
    
		$.ajax({
    
			async: true, // Boolean value , Indicates whether the request is processed asynchronously . The default is  true.
			url: "http://127.0.0.1:3000/", // Specify the time to send the request  URL
			type: "post",
			data: {
    
				'name':name,
				'password': passwords
			}, // Requested data , Data passed to the background 
			success: function(backdata) {
     // After the request is successful, the returned data will be encapsulated in the first parameter of the callback function 
				// adopt backdata To get the required data 
				console.log(backdata)
			},
			error: function(err) {
     // The function returned when the response is unsuccessful 
				console.log(err);
				console.log(' request was aborted ');
			},
			dataType: 'text' // Set the returned data type 
		})
	}
</script>

5. Click registration , After successful registration, as shown in the figure ：
Insert picture description here
6. Database added successfully
Insert picture description here
7. Add the same data again
Insert picture description here
notes ： The logic layer side must be clear , Otherwise it will be reported Error 1: Cannot set headers after they are sent to the client：
reason ： The client makes a request , The server gives two or more responses
Solution ： Clean up the excess number of responses ; Immediately after each response return Drop function

版权声明
本文为[It's never too late to be alone]所创，转载请带上原文链接，感谢
https://yzsam.com/2022/04/202204231303465650.html

边栏推荐

猜你喜欢

随机推荐