使用nodejs將CSV檔案匯入mysql資料庫

我正在嘗試使用 nodejs 將 CSV 檔案上傳到 MySQL 資料庫......它作業成功并添加了行，但它給了我一個錯誤。這是我的代碼：

//use express static folder
app.use(express.static("./public"))
 
// body-parser middleware use
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({
    extended: true
}))
 
 
db.connect(function (err) {
    if (err) {
        return console.error('error: '   err.message);
    }
    console.log('Connected to the MySQL server.');
})
 
//! Use of Multer
var storage = multer.diskStorage({
    destination: (req, file, callBack) => {
        callBack(null, './uploads/')    
    },
    filename: (req, file, callBack) => {
        callBack(null, file.fieldname   '-'   Date.now()   path.extname(file.originalname))
    }
})
 
var upload = multer({
    storage: storage
});
 
//! Routes start
 
//route for Home page
app.get('/', (req, res) => {
  res.sendFile(__dirname   '/index.html');
});
 
// upload csv to database
app.post('/uploadfile', upload.single("uploadfile"), (req, res) =>{
    UploadCsvDataToMySQL(__dirname   '/uploads/'   req.file.filename);
    console.log('CSV file data has been uploaded in mysql database '   err);
});
 
function UploadCsvDataToMySQL(filePath){
    let stream = fs.createReadStream(filePath);
    let csvData = [];
    let csvStream = csv
        .parse()
        .on("data", function (data) {
            csvData.push(data);
        })
        .on("end", function () {
            // Remove Header ROW
            csvData.shift();
  
            // Open the MySQL connection
            db.connect((error) => {
                if (error) {
                    console.error(error);
                } else {
                    let query = 'INSERT INTO files (File_ID, File_Name) VALUES ?';
                    db.query(query, [csvData], (error, response) => {
                        console.log(error || response);
                    });
                }
            });
             
            // delete file after saving to MySQL database
            // -> you can comment the statement to see the uploaded CSV file.
            fs.unlinkSync(filePath)
        });
  
    stream.pipe(csvStream);
}
 
//create connection
const PORT = process.env.PORT || 8000
app.listen(PORT, () => console.log(`Server is running at port ${PORT}`))

這是檔案上傳后PowerShell中出現的錯誤：

ReferenceError: err is not defined at C:\Users\DELL\Desktop\Advanced\AdvancedSeE\dbmanager\index.js:79:72 at Layer.handle [as handle_request] (C:\Users\DELL\Desktop\Advanced\AdvancedSeE \dbmanager\node_modules\express\lib\router\layer.js:95:5) 在下一個 (C:\Users\DELL\Desktop\Advanced\AdvancedSeE\dbmanager\node_modules\express\lib\router\route.js:137 :13) 在陣列。(C:\Users\DELL\Desktop\Advanced\AdvancedSeE\dbmanager\node_modules\multer\lib\make-middleware.js:53:37) 在監聽器 (C:\Users\DELL\Desktop\Advanced\AdvancedSeE\dbmanager\ node_modules\on-finished\index.js:169:15) 在 onFinish (C:\Users\DELL\Desktop\Advanced\AdvancedSeE\dbmanager\node_modules\on-finished\index.js:100:5) 在回呼 (C :\Users\DELL\Desktop\Advanced\AdvancedSeE\dbmanager\node_modules\ee-first\index.js:55:10) 在 IncomingMessage.oneevent (C:

uj5u.com熱心網友回復：

在以下區域中，您err在檔案中未定義的控制臺日志中添加了

// upload csv to database
app.post('/uploadfile', upload.single("uploadfile"), (req, res) =>{
   UploadCsvDataToMySQL(__dirname   '/uploads/'   req.file.filename);
   console.log('CSV file data has been uploaded in mysql database '   err); //<----- here err is not defined 
});

只需洗掉它并嘗試問題是否解決

標籤：javascript mysql 节点.js 网络 节点模块

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