mongodb 遇到问题-查询单个需要包装id

mongodb，get字符查询需要传入特定的包装id才能识别

const ObjectID = require('mongodb').ObjectID

exports.queryOne = (req, res) => {
    console.log(req.body)
    MongoClient.connect(url, function(err, client) {
            assert.equal(null, err);
            const db = client.db(dbName);
            // Get the documents collection
            const collection = db.collection('documents');
            const id = new ObjectID(req.params.id)
            console.log(id)
            // Find some documents
            collection.find({'_id':id}).toArray(function(err, docs) {
                assert.equal(err, null);
                res.status(200).json(docs)
                client.close();
            });
        });
    }