将上传的文件引用到新集合的 Multer gridfs 存储

Question

使用 multer gridfs 存储上传的文件我想将它引用到新创建的集合（电影）。我引用上传文件的文件 ID 与上传文件不同，即使电影收藏没有保存到数据库中。我引用上传的文件的文件 ID 与上传的文件不同，即使电影收藏没有保存在数据库中

//movie schema
    const mongoose = require('mongoose');
    const Schema = mongoose.Schema;

    const MovieSchema = new Schema({
    	description: {
    		type: String,
    	},
    	category: {
    		type: String,
    	},
    	token: {
    		type: String,
    	},
    	fileID: {
    		type: Schema.Types.ObjectId,
    		ref: "contents.files"
    	}
    });

    module.exports = movies = mongoose.model('movies', MovieSchema);



    let gfs;

    conn.once('open', () => {
        gfs = Grid(conn.db, mongoose.mongo);
        gfs.collection('contents');

    });



    const storage = new GridFsStorage({
        url: config.db,
        file: (req, file) => {
            return new Promise((resolve, reject) => {
            
                    const filename = req.body.fileName + path.extname(file.originalname);
                    const Description = req.body.Description
                    const fileInfo = {
                        filename: filename,
                        bucketName: 'contents',
                        metadata: req.body,
                        
                    }
                    resolve(fileInfo, Description);
                
            });
        }
    });
    const   upload = multer({
        storage
    });
    router.get('/', (req, res) => {
        res.render('index');
        console.log(req.body)
    });

    //** uploading file to the db */

    router.post('/', upload.any(), (req, res) => {
        
          
        const movie = new movies({
            description: "test",
            category: "test",
            fileID: gfs.files.id
        })
        
          movie.save()
    });

fileID 与上传的文件 Id 不同，并且集合未保存在 DB 中 fileID 与上传的文件 Id 不同，并且集合未保存在 DB 上 fileID 与上传的文件 Id 不同，集合也未保存保存在数据库中

Answer 1

它不起作用，因为您使这变得比需要的更复杂。文件中的引用是不必要的。您可以使用此代码完成相同的操作。

//movie schema
const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const MovieSchema = new Schema({
  description: {
    type: String,
  },
  category: {
    type: String,
  },
  token: {
    type: String,
  },
  fileID: {
    type: Schema.Types.ObjectId, // There is no need to create references here
  }
});

module.exports = movies = mongoose.model('movies', MovieSchema);

const storage = new GridFsStorage({
  url: config.db,
  file: (req, file) => {
    return new Promise((resolve, reject) => {  
      // if you are using a separate collection to store data 
      // there is no need to save this information on the metadata
      // because you'll probably never use it
      const filename = req.body.fileName + path.extname(file.originalname);
      const fileInfo = {
        filename: filename,
        bucketName: 'contents'
      }
      resolve(fileInfo);
    });
  }
});
const upload = multer({
  storage
});

router.get('/', (req, res) => {
  res.render('index');
  console.log(req.body)
});

//** uploading file to the db */
router.post('/', upload.any(), (req, res) => {
  const movie = new movies({
    description: req.body.Description,
    category: req.body.Category,
    // Grab the file id that was stored in the database by the storage engine as the reference to your file
    fileID: req.file._id
  })

  movie.save()
});

你不应该使用uploads.any(). 这将接受任何传入的文件。相反，您应该使用array,single或字段，具体取决于您发送的文件数量和用于发送它们的字段名称。

要稍后从数据库中读取该文件，您只需要查询您的Movies集合，并且该fileId字段具有一个标识符，您可以GridfsBucket在该openDownloadStream流中传递给该流并通过管道传递给响应，将使用该 ID 存储的文件返回给用户或使用在您的应用程序具有的任何业务逻辑中。