actually the module version is 2.0.49,but the selector has no option for it......

when I use updateOne like this:
var ObjectID = require('mongodb').ObjectID;
formDao.updateOne(

, {$set: postData}, function (err, reply)

);

throw err below:
{ [MongoError: After applying the update to the document {_id: ObjectId('574fe4f70ee6c41917c4dfeb') , ...}, the (immutable) field '_id' was found to have been altered to _id: "574fe4f70ee6c41917c4dfeb"] name: 'MongoError', message: 'After applying the update to the document {_id: ObjectId(\'574fe4f70ee6c41917c4dfeb\') , ...}, the (immutable) field \'_id\' was found to have been altered to _id: "574fe4f70ee6c41917c4dfeb"', driver: true, index: 0, code: 66, errmsg: 'After applying the update to the document {_id: ObjectId(\'574fe4f70ee6c41917c4dfeb\') , ...}, the (immutable) field \'_id\' was found to have been altered to _id: "574fe4f70ee6c41917c4dfeb"' }

but I try it on command line console:
db.form.update({_id:ObjectId('574fe4f70ee6c41917c4dfeb')},{$set:{_class:'mmm'}});

it works!

you konw what I mean,man,please resolve it, I almost confused with it a half day ~~~_{(>_<)}~~~