Cannot read property 'filename' of undefined Node js

Question

I have a problem with nodejs, when I want to make a post with an image, I have an error message "Cannot read property 'filename' of undefined" I do not see where my error is. this is my multer :

app.use(express.static('views/images'))
const storage = multer.diskStorage({
    destination: 'views/images',
    filename: function(req,file, cb){
        cb(null, file.fieldname + '_'+ Date.now()+path.extname(file.originalname));
    }
})

const upload = multer({storage: storage}).single('img');

here is my database.js

db.run(`
CREATE TABLE IF NOT EXISTS products (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT,
    description TEXT,
    image TEXT
)
`)

exports.uploadPost = function(name, description, Filename, callback){
    const query = "INSERT INTO products('name', 'description', 'image') VALUES (?,?,?)"
    const values =  [name, description, Filename]
    db.run(query,values, function(error){
        callback(error)
    })
}

and app.js

app.post('/products/create', (req,res) => {
    // req.file contains information of uploaded file
    // req.body contains information of text fields, if there were any
    upload(req, res, (err) => {
        const name = req.body.name
        const description = req.body.description
        const Filename = req.file.filename
        
        db.uploadPost(name, description, Filename, function(error){
            console.log(req.Filename)
            const id = this.lastID
            res.redirect('/products/'+id)
        })
    })
})

and HTML

<form action="/products/create" method="POST">
    <div>
        <label class="form-label" for="img">Select image:</label>
        <input class="form-input" type="file" id="img" name="img" required>
    </div>
</form>

Answer 1

添加 enctype="multipart\/form-data"

<form action="/products/create" method="POST" enctype="multipart/form-data">
        <div>
            <label class="form-label" for="img">Select image:</label>
            <input class="form-input" type="file" id="img" name="img" required>
        </div>
    </form>