我在将文件同时上传到pc和DB时遇到问题。
我在代码中使用了两个不同的模块
但是，使用两个单独的功能根本不是我的意图。因此，当我尝试将两个模块与基本代码组合在一起时，使用Multer进行文件上传有效，但我想将该文件上传到MongoDB，这需要由csv-to-json解决，这对我来说似乎没什么问题。
这是我的代码：
var express = require('express');
var multer = require('multer');
const csv = require('csvtojson');
// Import Mongodb
const mongoClient = require('mongodb').MongoClient,
assert = require('assert');
var filename = null;
var storage = multer.diskStorage({
destination: function(req, file, cb) {
cb(null, 'uploads/')
},
filename: function(req, file, cb) {
filename = Date.now() + '-' + file.originalname;
cb(null, filename)
console.log(filename);
}
})
var upload = multer({
storage: storage
})
var app = express();
app.get('/', (req, res) => {
res.sendFile(__dirname + '/index.html');
});
app.post('/', upload.single('file-to-upload'), function(req, res, next) {
// Mongodb Connection URL
const url = 'mongodb://localhost:27017/csvfilereader';
// Use connect method to connect to the Server
mongoClient.connect(url, (err, db) => {
assert.equal(null, err);
if (db) {
console.log("Connected correctly to server");
insertDocuments(db, function() {
db.close();
});
} else {
console.log('\n', 'Problem with connection', err)
}
});
const insertDocuments = (db, callback) => {
// Get the documents collection
let collection = db.collection('uploaded');
// CSV File Path
const csvFilePath = 'uploads/' + filename;
console.log(csvFilePath);
/**
* Read csv file and save every row of
* data on mongodb database
*/
csv()
.fromFile(csvFilePath)
.on('json', (jsonObj) => {
collection.insert(jsonObj, (err, result) => {
if (err) {
console.log(err);
} else {
console.log('suceess');
res.redirect('/');
filename = null;
}
});
})
.on('done', (error) => {
console.log('end')
})
}
});
app.listen(3200);<!--
HTML Code that runs on Root
-->
<html lang="en">
<head>
<title>Simple Multer Upload Example</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<form action="/" enctype="multipart/form-data" method="post">
<input type="file" name="file-to-upload">
<input type="submit" value="Upload">
</form>
</body>
</html>您需要通过multer传递的请求访问文件名。您的filename变量不指向任何对象。
req.file.filename将允许访问由multer上传的文件。
更新的代码：
var express = require("express");
var multer = require("multer");
const csv = require("csvtojson");
// Import Mongodb
const MongoClient = require("mongodb").MongoClient,
assert = require("assert");
var filename = null;
var storage = multer.diskStorage({
destination: function(req, file, cb) {
cb(null, "uploads/");
},
filename: function(req, file, cb) {
filename = Date.now() + "-" + file.originalname;
cb(null, filename);
},
});
var upload = multer({
storage: storage,
});
var app = express();
app.get("/", (req, res) => {
res.sendFile(__dirname + "/index.html");
});
app.post("/", upload.single("file-to-upload"), function(req, res, next) {
// Connection URL
const url = "mongodb://localhost:27017";
console.log("Multer", req.file.filename);
// Database Name
const dbName = "csvreader";
// Create a new MongoClient
const client = new MongoClient(url, { useNewUrlParser: true });
// Use connect method to connect to the Server
client.connect(function(err) {
assert.equal(null, err);
console.log("Connected successfully to database");
const db = client.db(dbName);
insertDocuments(db, function() {
console.log("Closing connection");
client.close();
});
});
const insertDocuments = (db, callback) => {
// Get the documents collection
const collection = db.collection("uploaded");
// CSV File Path
const csvFilePath = "uploads/" + filename;
console.log("Reading file from ", csvFilePath);
/**
* Read csv file and save every row of
* data on mongodb database
*/
csv()
.fromFile(csvFilePath)
.then(jsonObj => {
console.log(jsonObj);
collection.insert(jsonObj, (err, result) => {
if (err) {
console.log(err);
} else {
console.log("suceess");
res.redirect("/");
filename = null;
callback();
}
});
})
.catch(err => {
//error reading file
console.log(err);
});
};
});
app.listen(3200, () => {
console.log("Server working at port 3200");
});