使用 Node.js 从 MySQL 中提取数据并显示在 HTML 页面上 [英] Extract data from MySQL using Node.js and display on HTML page
问题描述
我试图从 MySQL 中提取数据并将其显示在我的 HTML 页面上，但是当我在我的浏览器 http://localhost:3000 上运行下面的代码时，数据没有显示在我的页面.如果有人能帮我解决这个问题，我将不胜感激.
I am trying to extract data from MySQL and display it on my HTML page, but when I run the code below on my browser http://localhost:3000, the data does not display on my page. I would appreciate if somebody could help me solve this problem.
index.html
<!DOCTYPE>
<html>
<head>
<title>Data from MySQL</title>
</head>
<body>
<div id="output_message"></div>
</body>
</html>
app.js
var express = require('express');
var app = express();
var mysql = require('mysql');
var bodyParser = require('body-parser');
var urlencodedParser = bodyParser.urlencoded({ extended: false });
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: false}));
app.use('/', express.static(__dirname + '/'));
app.set('view engine', 'html');
var connection = mysql.createConnection({
host: "localhost",
user: "root",
password: "",
database: "mywebsite"
});
connection.connect();
app.get('/',(req, res) => {
connection.query("SELECT * FROM chat",(err, result) => {
if(err) {
console.log(err);
res.json({"error":true});
}
else {
console.log(result);
res.json(result);
}
});
});
app.listen(3000, function () {
console.log('Connected to port 3000');
});
推荐答案
您需要考虑多个因素:
1 - 当您想使用通过 HTML 文件发送的 POST 方法时，您必须有一个
1 - When you want to use a POST method sent through a HTML file you must have a
<form action="Name of your processing file" method="POST">YOUR FORM HERE</form>
然而；如果您只是尝试调用数据库并获取数据，则只需执行
However; if you simply trying to call a db and get your data then just perform
您在 GET 方法中的逻辑如下:
your logic within the GET method as following:
app.get('/',(req, res) => {
connection.connect(function(err) {
if(err) throw err;
else {
connection.query("SELECT * FROM chat",(err, result) => {
if(err) {
console.log(err);
res.json({"error":true});
}
else {
console.log(result);
res.json(result);
}
});
}
});
});
*** 你可能会问 index.html 怎么样.对此有两种回应:
*** You may ask what about the index.html . There are two responses for that :
1 - 当你想发送文件时使用 res.sendFile(__dirname + "/YOURPAGE-Name.html");
1 - Use res.sendFile(__dirname + "/YOURPAGE-Name.html"); when you want to send a file
结果
示例:
app.get("/",(req, res) => {
res.sendFile(__dirname + "/Welcome.html");
});
欢迎.html
<!DOCTYPE>
<html>
<head>
<title>Data from MySQL</title>
</head>
<body>
<p>Welcome to my page</p>
</body>
</html>
2 - 使用 res.sendFile(__dirname + "/index.html"); 当你想要获取
2 - Use res.sendFile(__dirname + "/index.html"); when you want to get the
初始页面，以便您可以在要处理的应用程序中使用表单
initial page so then you can have forms within the application that you want to process
示例:
app.get("/",(req, res) => {
res.sendFile(__dirname + "/index.html");
});
index.html
<!DOCTYPE>
<html>
<head>
<title>Data from MySQL</title>
</head>
<body>
<form action="/" method="post">
//YOUR FORM HERE
</form>
</body>
</html>
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