javascript - 使用 Node 、mysql、express 和纯 js 从数据库中删除一行

Question

我正在使用 node、express、mysql 创建一个简单的应用程序。

我正在尝试创建一个可以从我的数据库中删除一行的路由，我写了一个纯 javascript xhr。

当我测试它时，我不断收到以下错误消息

POST http://localhost:3000/article/22 404 (Not Found)

这是我的:

主要.js

function handleDeleteClick(e, userId) {
    e.preventDefault(); // Prevent default behaviour of this event (eg: submitting the form

    // Perform the AJAX request to delete this user
    var target = e.target;
    var id = target.getAttribute('data-id');
    var page = '/article/' + id;
    var parameters = 'delete=true';
    var xmlhttp = new XMLHttpRequest();

    if (confirm('Are you sure you want to delete this?') == true) {
        xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                // Request completed
            }
        }
        xmlhttp.open("POST", page, true);
        xmlhttp.send(parameters);
    }
}

和路由 app.js

app.delete('/article/:id', function(req, res) {
    con.query(`DELETE FROM posts WHERE posts.id = ${req.params.id}`,
        function(err, result, fields) {
            if (err) {
                console.log(err);
            } else {
                console.log("deleted Record: " + result.affectedRows);
                res.redirect('/')
            }
        });
});

我错过了什么？

非常感谢帮助! 谢谢。

Answer 1

在 main.js 文件中将 POST 更改为 DELETE:

xmlhttp.open("DELETE", page, true);

您收到此 404 NOT FOUND 错误，因为路由 POST/article/:id 不存在(它是 DELETE/article/:id).

Note: Your DELETE-query is vulnerable for SQL-injection attacks escaping-query-values

转义查询值:

con.query('DELETE FROM posts WHERE posts.id = ?', [req.params.id]); 

Note: Actually, correct http status for this case is 405 METHOD NOT ALLOWED, but express by default doesn't distinguish those cases