error ReferenceError:未定义ObjectID

Question

我想用GridJS上传图片.我正在使用https://www.npmjs.org/package/gridfs-stream.它给了我error ReferenceError: ObjectID is not defined.

我是初学者,所以不知道最新情况.

如何解决这个错误？

var Grid = require('gridfs-stream');
    var conn = mongoose.createConnection('localhost', 'Test', 27017);
    var gfs = Grid(conn.db, mongoose);

    var fileId = new ObjectID(uniqId);
    var fileType = req.header('X-File-Type');
    var fileName = req.header('X-File-Name');
    var uniqId = req.param('uniqId', '112211112111');

    console.log('upload start');
    // streaming to gridfs
    var writestream = gfs.createWriteStream(fileId, [{ "content_type": fileType, "metadata": { "fileName": fileName, "uploaded_at": (new Date()).toString() } }]);
    fs.createReadStream('/some/path').pipe(writestream);

    // streaming from gridfs
    var readstream = gfs.createReadStream(fileId, [{ "content_type": fileType, "metadata": { "fileName": fileName, "uploaded_at": (new Date()).toString() } }]);

    //error handling, e.g. file does not exist
    readstream.on('error', function (err) {
        console.log('An error occurred!', err);
        throw err;
    });

    readstream.pipe(response);
    console.log('upload done');

Answer 1

ObjectID它不是一个全局变量,它由mongoose定义(参见文档):

var fileId = mongoose.Types.ObjectId();

Answer 2

尝试这个。它将在您的代码中正常工作。

\n

// ObjectID deprecated \xe2\x9d\x8c\nvar ObjectId = require(\'mongodb\').ObjectID;\n\n

\n

// ObjectiD \xe2\x9c\x85\nconst ObjectId = require(\'mongodb\').ObjectId;\n

\n

Answer 3

不是直接解决方案,而是浪费了10分钟的小错误:

var ObjectId = require('mongodb').ObjectID;

我声明了一个带有小d的变量ObjectId 但是在使用变量时,我尝试使用大写D的ObjectID.

Answer 4

var ObjectId = require('mongodb').ObjectId;

ObjectID（大写“D”）已弃用。请改用 ObjectId（小写“d”）。（来源：@types/bson 包

Answer 5

您可以使用下面的代码来获取ObjectId

const ObjectId = require('mongodb').ObjectId;

如果你想使用它

db.collection.deleteOne({_id: new ObjectId(req.params._id)})
.then(data => {
  res.send({status: "Success", data});
})
.catch(err => {
  console.log(err)
});