MongoDB错误:无法在字符串上创建属性"_id"

问题描述

我在Heroku上使用Node.js和Express，以及MongoDB插件.我的数据库连接工作正常，我可以成功地推送一些数据，但不能成功地推送其他数据.

I'm using Node.js and Express on Heroku, with the MongoDB addon.My database connection works fine and I can successfully push some data in, but not other.

这是数据库连接:

mongodb.MongoClient.connect(mongoURI, function (err, database) {
if (err) {
    console.log(err);
    process.exit(1);
}

// Save database object from the callback for reuse.
db = database;
console.log("Database connection ready");

// Initialize the app.
var server = app.listen(process.env.PORT || dbport, function () {
    var port = server.address().port;
    console.log("App now running on port", port);
});
});

我可以像这样成功地将Twitter API响应推入数据库:

I can successfully push my Twitter API response into the database like this:

db.collection(TWEETS_COLLECTION).insert(data);

(数据"只是一个JSON变量)

('data' is just a JSON variable)

但是当我尝试用相同的方法将另一个JSON变量推入数据库时​​，出现错误.代码:

But when I try to push another JSON variable into the database in the same method, I get an error. Code:

var jsonHash = '{"hashtag":"","popularity":1}';
var objHash = JSON.parse(jsonHash);
objHash.hashtag = req.body.hashtag;
JSON.stringify(objHash);
collection(HASHTAG_COLLECTION).insert(jsonHash);

错误:

有什么想法我在做什么错吗?

Any ideas what I'm doing wrong?

推荐答案

我不知道您从哪里获取jsonHash变量，但我认为您在此处进行了不必要的JSON处理.您还要插入错误的变量，要插入objHash这是要插入的有效对象，现在要插入jsonHash，这只是一个字符串. JSON.stringify(objHash);没有做任何事情，因为您没有保存从函数返回的JSON.我想你想要这样的东西吗?

I don't know where you are getting the jsonHash variable from but I think you are doing unecessary JSON-handling here. You are also inserting the wrong variable, you want to insert objHash which is a valid object to insert, now you are inserting jsonHash which is just a string. JSON.stringify(objHash); is not doing anything as you are not saving the JSON returned from the function. I think you want something like this?

var objHash = {
      hashtag: "",
      popularity:1
};
objHash.hashtag = req.body.hashtag;
collection(HASHTAG_COLLECTION).insert(objHash);

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