Node.js/Mongodb插入回调未定义的回调

当我运行下面的简单代码插入一个新文档时:

collectionUsers.insert({'name':'john'},function(err,records){
    if (err) throw err;
    console.log("Id of new document added =  " + records[0]._id);
});

我收到以下错误:

catch(err) { process.nextTick(function() { throw err}); }
                                             ^
TypeError: Cannot read property '_id' of undefined

回调函数不返回数组吗？我只是想获取新文档的id并将其保存在变量中以备将来使用.谢谢你的帮助.

或者,如果我使用insertOne,我得到此输出:添加新文档的ID = {"ok":1,"n":1}

但我想使用插入...

有一个ops对象records包含插入的doc/docs.

尝试:

collectionUsers.insert({'name':'john'},function(err,records){
   // You can explore more here
   console.log("record contents",JSON.stringify(records,null,4));
   // Desired output
   console.log("Id of new document added =  " + records.ops[0]._id);
});