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使用multer上传多个文件，但来自不同的字段？

node.jsmulter
38

我该如何让multer接受多个文件类型字段的文件？

以下是我在node.js中使用multer上传单个文件的代码：

var storage =   multer.diskStorage({
  destination: function (req, file, callback) {
    callback(null, './public/uploads');
  },
  filename: function (req, file, callback) {
    callback(null, file.fieldname + '-' + Date.now());
  }
});

var upload = multer({ storage : storage });

app.post('/rest/upload', upload.array('video', 1), function(req, res, next){
    ...
}

从以下表单中，只有视频字段有值的情况下（如果我同时指定两个字段，会得到一个“意外字段”错误）：

<form action="/rest/upload" method="post" enctype="multipart/form-data">
   <label>Video file: </label> <input type="file" name="video"/> 
   <label>Subtitles file: </label> <input type="file" name="subtitles"/> 
   <input type="submit"/>
</form>
文档中并未清晰阐明该如何处理此问题？如果有任何建议，将不胜感激。顺便说一句，我已尝试使用以下参数变化，但没有成功：
app.post('/rest/upload', [upload.array('video', 1), upload.array('subtitles', 1)] ...
app.post('/rest/upload', upload.array('video', 1), upload.array('subtitles', 1), ...
app.post('/rest/upload', upload.array(['video', 'subtitles'], 1),  ...
7个回答
75

你需要的是upload.fields()：

app.post('/rest/upload',
         upload.fields([{
           name: 'video', maxCount: 1
         }, {
           name: 'subtitles', maxCount: 1
         }]), function(req, res, next){
  // ...
}
扩展名丢失，请更改。谢谢。 - Rishav Kumar
4
你能具体说明一下吗？你是在指文件扩展名还是API已经发生了变化或者其他方面的内容？ - mscdex
21

使用 Multer 从不同页面的两个表单字段上传文件 在此示例中，我有两个字段 - 简历和图片。简历在一个表单中，图片在另一个表单中。两者都在不同的页面上。 首先导入依赖项

const path = require('path'); // for getting file extension
const multer = require('multer'); // for uploading files
const uuidv4 = require('uuidv4'); // for naming files with random characters

定义 fileStorage 和 fileFilter：

const fileStorage = multer.diskStorage({
  destination: (req, file, cb) => { // setting destination of uploading files        
    if (file.fieldname === "resume") { // if uploading resume
      cb(null, 'resumes');
    } else { // else uploading image
      cb(null, 'images');
    }
  },
  filename: (req, file, cb) => { // naming file
    cb(null, file.fieldname+"-"+uuidv4()+path.extname(file.originalname));
  }
});

const fileFilter = (req, file, cb) => {
  if (file.fieldname === "resume") { // if uploading resume
    if (
      file.mimetype === 'application/pdf' ||
      file.mimetype === 'application/msword' ||
      file.mimetype === 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'
    ) { // check file type to be pdf, doc, or docx
      cb(null, true);
    } else {
      cb(null, false); // else fails
    }
  } else { // else uploading image
    if (
      file.mimetype === 'image/png' ||
      file.mimetype === 'image/jpg' ||
      file.mimetype === 'image/jpeg'
    ) { // check file type to be png, jpeg, or jpg
      cb(null, true);
    } else {
      cb(null, false); // else fails
    }
  }
};

multer 的中间件

app.use(
  multer(
    { 
      storage: fileStorage, 
      limits:
        { 
          fileSize:'2mb' 
        }, 
      fileFilter: fileFilter 
    }
  ).fields(
    [
      { 
        name: 'resume', 
        maxCount: 1 
      }, 
      { 
        name: 'image', 
        maxCount: 1 
      }
    ]
  )
);

然后调用你的路由。为了安全起见，你可能需要加入csrf保护或者身份验证。但是这应该可以正常运行。

1
非常感谢您的澄清，它帮助我更好地理解了。在出现错误的情况下（禁止在else块中作为唯一语句使用if语句（no-lonely-if）），您可以通过使用三元运算符来修复它，对于控制器的问题，我使用了resume：req.files.resume，image：req.files.image。 - Emmanuel Neni
13

如果您希望从同一表单中上传多个文件/图片，我已使用以下代码，并且它可以正常工作。图像的路径存储在数据库中；我将跳过数据库路径并直接进入上传功能以及如何将字段传递给保存函数。

    const path = require('path');
    const multer = require('multer');
    const storage = multer.diskStorage({
        destination: (req, file, cb) => {
           if (file.fieldname === "profile") {
               cb(null, './uploads/profiles/')
           }
           else if (file.fieldname === "natid") {
               cb(null, './uploads/ids/');
           }
           else if (file.fieldname === "certificate") {
               cb(null, './uploads/certificates/')
           }
        },
        filename:(req,file,cb)=>{
            if (file.fieldname === "profile") {
                cb(null, file.fieldname+Date.now()+path.extname(file.originalname));
            }
          else if (file.fieldname === "natid") {
            cb(null, file.fieldname+Date.now()+path.extname(file.originalname));
          }
          else if (file.fieldname === "certificate") {
            cb(null, file.fieldname+Date.now()+path.extname(file.originalname));
          }
        }
    });
    const upload = multer({
        storage: storage,
        limits: {
            fileSize: 1024 * 1024 * 10
        },
        fileFilter: (req, file, cb) => {
            checkFileType(file, cb);
        }
    }).fields(
        [
            {
                name:'profile',
                maxCount:1
            },
            {
                name: 'natid', maxCount:1
            },
            {
                name: 'certificate', maxCount:1
            }
        ]
    );
    
    function checkFileType(file, cb) {
        if (file.fieldname === "certificate") {
            if (
                file.mimetype === 'application/pdf' ||
                file.mimetype === 'application/msword' ||
                file.mimetype === 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'
              ) { // check file type to be pdf, doc, or docx
                  cb(null, true);
              } else {
                  cb(null, false); // else fails
              }
        }
        else if (file.fieldname === "natid" || file.fieldname === "profile") {
            if (
                file.mimetype === 'image/png' ||
                file.mimetype === 'image/jpg' ||
                file.mimetype === 'image/jpeg'||
                fiel.mimetype==='image/gif'
              ) { // check file type to be png, jpeg, or jpg
                cb(null, true);
              } else {
                cb(null, false); // else fails
              }
            }
        }
    //at the save function 

 upload(req, res, (err) => {
        if (err) {
            console.log(err);
        } else {
            if (req.file == "undefined") {
                console.log("No image selected!")
            } else {
                let datecreated = new Date();
                let fullnames = req.body.firstname + ' ' + req.body.lastname;
                let formatedphone = '';
                let phone = req.body.personalphone;
                if (phone.charAt(0) == '0') {
                    formatedphone = '+254' + phone.substring(1);
                } else if ((phone.charAt(0) == '+') && (phone.length > 12 || phone.length <= 15)) {
                    formatedphone = phone
                }
                let teachers = {
                    "teacherid": teacherid,
                    "schoolcode": req.body.schoolcode,
                    "fullnames": fullnames,
                    "email": req.body.email,
                    "dateofbirth": req.body.dateofbirth,
                    "nationalid": req.body.nationalid,
                    "personalphone": formatedphone,
                    "profile": req.files.profile[0].path,
                    "natid": req.files.natid[0].path,
                    "certificate":req.files.certificate[0].path
                }
                connection.query('INSERT INTO teachers SET ?', teachers, (error, results, fields) => {`enter code here`
                    if (error) {
                        res.json({
                            status: false,
                            message: 'there are some error with query'
                        })
                        console.log(error);
                    } else {console.log("Saved successfully");
}
你能澄清一下这段代码块末尾发生了什么吗？至少，缩进似乎有问题。但是，还有一个配置块与函数无关。我猜你的评论是关于将其放置在save()函数中的？如果是这样，我建议将其拆分成一个单独的代码块。 - Jeremy Caney
这里是完整的保存函数：以下 - Wabz18
谢谢！您可以（并且在这种情况下应该）编辑您的答案，将Save()函数作为同一答案的一部分包含进去。这样，它们不会随着时间的推移而分离。您能做到吗？ - Jeremy Caney
1
你的回答应该包含解释，就像mhmdk在他们的回答中所做的那样。以目前的形式，它有被踩的风险。 - Andre M
6

这对我很有帮助。完整的例子：

var multer = require('multer')
var storage = multer.diskStorage({


destination: function(req, file, callback) {
    callback(null, './public/audio');
  },
  filename: function(req, file, callback) {
    console.log(file);
    if(file.originalname.length>6)
      callback(null, file.fieldname + '-' + Date.now() + file.originalname.substr(file.originalname.length-6,file.originalname.length));
    else
      callback(null, file.fieldname + '-' + Date.now() + file.originalname);

  }
});

const upload = multer({ storage: storage });


router.post('/save/audio',upload.fields([{
  name: 'audio', maxCount: 1
}, {
  name: 'graphic', maxCount: 1
}]) ,(req, res) => {
  
  const audioFile = req.files.audio[0];
  const audioGraphic = req.files.graphic[0];
  const fileName = req.body.title;


  saveAudio(fileName,audioFile.filename,audioGraphic.filename,req.body.artist,function (error,success) {
    req.flash('success','File Uploaded Successfully')

    res.redirect('/')
  });

})
4
我之前没有这样做，但我会采用uploads.fields()方法，因为文档表明any()可能不是最好的处理和安全性方面的选择。 - Andre M
0

我只需要将上传字段存储在一个数组中

const express = require("express"); 
 const category_route = express(); 
  
 const bodyParser = require('body-parser'); 
 category_route.use(bodyParser.json()); 
 category_route.use(bodyParser.urlencoded({extended:true})); 
 const controller = require('../Controller/Category'); 
 const Multer = require('multer') 
 const Path = require('path'); 
 const multer = require("multer"); 
  
 category_route.use(express.static('public')); 
  const storage = multer.diskStorage({ 
     destination : function(req,files,cb){ 
         cb(null,Path.join(__dirname,'../public/category'),function(err,sucess){ 
             if(err){ 
                 throw err; 
             } 
         }); 
     }, 
     filename:function(req,files,cb){ 
         const name = Date.now()+'-'+ files.originalname; 
         cb(null,name, function(err, sucess){ 
             if(err){ 
                 throw err; 
             } 
         }); 
     }  
  }); 
  
  const upload = multer({storage:storage}) 
  
  
 category_route.post('/add-category',upload.fields([ 
     { 
       name: "icon", 
       maxCount: 1, 
     }, 
     { 
       name: "banner", 
       maxCount: 1, 
     } 
   ]), controller.addCategory); 
  
  
 module.exports = category_route;

/* 控制器代码 */

const Category = require("../Model/Category"); 
  
 const addCategory = async (req, res) => { 
   try { 
  
     var arrIcon = []; 
     for(let i=0; i<req.files.length; i++){ 
       arrIcon[i] = req.files[i].filename; 
     } 
     var arrBanner = []; 
     for(let j=0; j<req.files.length; j++){ 
       arrBanner[j] = req.files[j].filename; 
     } 
  
     const catData = await Category.find(); 
      
     if (catData.length > 0) { 
       let checking = false; 
       catData.every((i) => { 
         if (i.name.toLowerCase() === req.body.name.toLowerCase()) { 
           checking = true; 
           console.log("FOUND"); 
           return false; 
         } 
         console.log("NOT-FOUND"); 
         return true; 
       }); 
       if (checking === false) { 
         const data = new Category({ 
           name: req.body.name, 
           camission: req.body.camission, 
           icon: arrIcon, 
           banner: arrBanner, 
           mtitel: req.body.mtitel, 
           mdiscp: req.body.mdiscp, 
         }); 
         const result = await data.save(); 
         res.send(result); 
       } else { 
         res.send("Category is Already exieet"); 
       } 
     } else { 
       const data = new Category({ 
         name: req.body.name, 
         camission: req.body.camission, 
         icon: arrIcon, 
         banner: arrBanner, 
         mtitel: req.body.mtitel, 
         mdiscp: req.body.mdiscp, 
       }); 
       const result = await data.save(); 
       res.send(result); 
     } 
   } catch (error) { 
     console.log(error); 
     res.send("somthing Wrong"); 
   } 
 }; 
 module.exports = { addCategory };
1
你的回答可以通过添加更多关于代码的信息以及它如何帮助提问者来改进。 - Tyler2P
-5
upload(req, res, (err) => {
        if (err) {
            console.log(err);
        } else {
            if (req.file == "undefined") {
                console.log("No image selected!")
            } else {
                let datecreated = new Date();
                let fullnames = req.body.firstname + ' ' + req.body.lastname;
                let formatedphone = '';
                let phone = req.body.personalphone;
                if (phone.charAt(0) == '0') {
                    formatedphone = '+254' + phone.substring(1);
                } else if ((phone.charAt(0) == '+') && (phone.length > 12 || phone.length <= 15)) {
                    formatedphone = phone
                }
                let teachers = {
                    "teacherid": teacherid,
                    "schoolcode": req.body.schoolcode,
                    "fullnames": fullnames,
                    "email": req.body.email,
                    "dateofbirth": req.body.dateofbirth,
                    "nationalid": req.body.nationalid,
                    "personalphone": formatedphone,
                    "profile": req.files.profile[0].path,
                    "natid": req.files.natid[0].path,
                    "certificate":req.files.certificate[0].path
                }
                connection.query('INSERT INTO teachers SET ?', teachers, (error, results, fields) => {
                    if (error) {
                        res.json({
                            status: false,
                            message: 'there are some error with query'
                        })
                        console.log(error);
                    } else {

console.log('保存成功');

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