Question

我有此代码：

<a class="btn-primary btn" href="/employer/booth/<%= user._id.toString() %>"
        <% console.log(typeof user._id, user._id) %>
   target="_blank">
    Preview your booth
</a>

此console.log的结果是：object 5bc9d28270e5375dfbfe17fd

为什么？为什么用护照创建的通用_id显然是字符串，却被当作对象？

我尝试做.toString()，但这在路由器中引起了另一个错误。这是代码：

router.get('/booth/:emp_id', async (req, res, next) => {
    const mongoose = require('mongoose');
    // For reports
    const {emp_id} = req.params;
    console.log('here', emp_id);
    console.log(typeof  emp_id);
    console.log(JSON.stringify(emp_id));
    const eventId = await GeneralInfo.findOne().then(r => r.activeEventId).catch(e => console.log(e));
    const event = await Event.findById(eventId).catch(e => console.log(e));
    Event.updateOne({'attendants.employers.id': mongoose.Types.ObjectId(emp_id)}, {$addToSet: {"attendants.employers.$.boothVisits": req.user._id}}, {$upsert: true}).catch(e => console.log(e));
    var postings = await Posting.find({
        'creatorId': emp_id,
        'visible': true,
        'eventId': eventId,
    }).catch(e => console.log(e));
    const acc = await Account.findById(emp_id);
    // const logo = await functions.downloadFile(req, res);
    const logo = await functions.downloadFile(acc.employer.logo);
    console.log(logo);
    res.render('users/employer/booth', {
        title: 'Employer Booth',
        user: req.user,
        postings: postings,
        employer: acc,
        event: event,
        logo: logo,
    });
});

如果我这样做，那么传递一个字符串，我得到这个：

(node:15508) UnhandledPromiseRejectionWarning: Error: Argument passed in must be a single String of 12 bytes or a string of 24 hex characters
at new ObjectID (/home/alex/Documents/Projects/ontario-job-portal/node_modules/mongodb-core/node_modules/bson/lib/bson/objectid.js:57:11)
at ObjectID [as ObjectId] (/home/alex/Documents/Projects/ontario-job-portal/node_modules/mongodb-core/node_modules/bson/lib/bson/objectid.js:38:43)
at router.get (/home/alex/Documents/Projects/ontario-job-portal/routes/employer.js:68:68)
at <anonymous>

由于某种原因，req.params.emp_id是[object Object]。如果我尝试JSON.stringify，我会得到"[object Object]"，所以这无济于事。

这是mongoDB中的_id字段

"_id": {
    "$oid": "5bc9d28270e5375dfbfe17fd"
},

那么如何将用户的_id作为字符串传递？

Answer 1

要获取id的十六进制表示，可以使用.valueOf()。这里有更多方法和示例：https://docs.mongodb.com/manual/reference/method/ObjectId.valueOf/#ObjectId.valueOf

节点读取字符串作为对象

1 个答案: