使用nodeJs的“MulterError：意外字段”

Answer 1

我认为您需要向

Content-type

添加一个

'multipart/form-data' 

标头，您还应该将图像文件附加为

'file'

而不是

'image'

，以便您的文件应像这样编辑：

let forms = document.querySelectorAll('form');
let divisionIdInput = form.querySelector('#divisionIdInput');
let imageInput = form.querySelector('#imageInput');

formData.append('file', imageInput.files[0], imageInput.files[0].name);

const divisionId = divisionIdInput.value;
fetch(`/divisionData/${divisionId}`, {
  method: 'POST',
  headers: {
      'Content-Type': 'multipart/form-data',
    },
  body: formData,
})
  .then(response => {
    if (!response.ok) throw new Error('Error inserting data');
    return response.text();  // Read the response as text
  })
  .then(responseText => {
    console.log('Response from server:', responseText);
  })
  .catch(error => {
    console.error('Error:', error);
  });

你还应该将你的express函数包装在try-catch范围内，以发现后端的问题：

app.post('/divisionData/:divisionId', upload.single('image'), (req, res) => {
    try{
    const image = req.file.buffer;
    const contentType = req.file.mimetype;
    const { divisionId } = req.body;

    // Check if any of the values are null
    if (divisionId === undefined || image === undefined) {
        res.send('All fields must have values.');
        return;
    }

    const insert_user_query = "INSERT INTO divisions (divisionId, image, contentType) VALUES (?, ?, ?)";
    const values = [divisionId, image, contentType];
    conn.query(insert_user_query, values, (err, result) => {
        if (err) {
            console.error("Database error:", err);
            return res.json({ error: "Failed while inserting data into database! Try to send files again." });
        }

        return res.json({ success: true });
    });
    }catch(err){
      return  res.status(500).json({ error: `Internal Server Error ${err}` });
    }
});