Question

node.js的新手，并学习如何将mysql与node一起使用。我有一个form.html，它有两个按钮来输入department_no和department_name。我可以成功插入mysql数据库，但是不知道如何删除特定的dept_no。我要执行的操作是输入dept_no和dept_name，然后根据DELETE从我的数据库中输入dept_no。另外，我希望能够检查用户输入的内容，以确保它是有效的dept_no和dept_name。任何有关如何入门或研究如何做到这一点的想法都将非常有帮助。我将在下方粘贴我的node.js和form.html。

node.js

// DELETE BELOW
app.delete("/deleteEmp/", (req, res) => {
  console.log("Department number is " + req.body.department_no);
  console.log("Department name is " + req.body.department_name);

  const deptNumber = req.body.department_no;
  const deptName = req.body.department_name;

  const connection = mysql.createConnection({
    host: "localhost",
    user: "root",
    database: "employees"
  });

  const queryString = "DELETE departments WHERE dept_no = ?";
  connection.query(queryString, [department_no], (err, results, fields) => {
    if (err) {
      console.log("Could not delete" + err);
      res.sendStatus(500);
      return;
    }
    console.log("Deleted department_no with dept_name");
    res.end();
  });
});

form.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>SQLFORM</title>
    <style>
      #space {
        margin-top: 20px;
      }
    </style>
  </head>
  <body>
    <div>Fill Form Below</div>
    <hr />
    <div id="space">
      <form action="/deleteEmp" method="DELETE">
        <input placeholder="Enter Department Number" name="department_no" />
        <input placeholder="Enter Department Name" name="department_name" />
        <button>Submit</button>
      </form>
    </div>
  </body>
</html>

Answer 1

HTML表单通常不支持DELETE请求。节点应用可以使用类似的变通方法-https://github.com/expressjs/method-override

Answer 2

另一种替代方法是执行对允许的方法没有限制的AJAX请求。简化示例：

document.querySelector('#space form').addEventListener('submit', (event) => {
  event.preventDefault();

  let formData = new FormData();
  formData.append('department_no', document.querySelector("input[name='department_no']").value);
  formData.append('department_name', document.querySelector("input[name='department_name']").value);

  fetch('https://yoururl.com/deleteEmp', {
    method: 'DELETE',
    headers: {
      "Content-type": "application/x-form-urlencoded"
    },
    body: formData
  });
});

在SQL数据库上使用Node.js创建DELETE请求

2 个答案: