Question

我正在根据自己的ID比较名为user和bloodrequest的两个文档，如果它们匹配，则在具有相同ID的表bloodrequest中显示值。我的问题是，我试图将当前登录的用户存储到这样的var中：var permit = mainUser.branch_id，然后使用$where语句，使用此语句：this.chapter_id == permit，但给我错误。 / p>

MongoError: TypeError: mainUser is undefined :

这是我的代码，我唯一的问题是如何将mainUser.branch_id传递给var permit，我才刚刚开始学习

router.get('/bloodapprovedrequestmanagement', function(req, res) {
    User.find({}, function(err, users) {
        if (err) throw err;
        User.findOne({ username: req.decoded.username }, function(err, mainUser) {
            if (err) throw err;
            if (!mainUser) {
                res.json({ success: false, message: 'No user found' });
            } if (mainUser.branch_id === '111') {

                Bloodrequest.find({$where: function(err) {
                        var permit = mainUser.branch_id//gives me error here
                        return (this.request_status == "approved" && this.chapter_id == permit) }}, function(err, bloodrequests) {
                    if (err) throw err;
                    Bloodrequest.findOne({ patient_name: req.decoded.patient_name }, function(err, mainUser) {
                        if (err) throw err;
                        res.json({ success: true, bloodrequests: bloodrequests });
                    });
                });

            }
        });
    });
});

Answer 1

在本地范围之外声明变量。

 `router.get('/bloodapprovedrequestmanagement', function(req, res) {
           var permit;
            User.find({}, function(err, users) {
                if (err) throw err; 
                User.findOne({ username: req.decoded.username }, function(err, mainUser) {
                    if (err) throw err; 
                    if (!mainUser) {
                        res.json({ success: false, message: 'No user found' }); 
                    } 
                    if(mainUser.branch_id === '111') {
                        permit = mainUser.branch_id;
                        Bloodrequest.find({$where: function(err) {
                            return (this.request_status == "approved" && this.chapter_id == permit) }}, function(err, bloodrequests) {
                            if (err) throw err; 
                            Bloodrequest.findOne({ patient_name: req.decoded.patient_name }, function(err, mainUser) {
                                if (err) throw err; 
                                res.json({ success: true, bloodrequests: bloodrequests });                     
                            });
                        });

                    }
                });
            });
        });`

Answer 2

将您的callback转换为async await更加简单。

router.get('/bloodapprovedrequestmanagement', function async(req, res) {
   try {
    var permit;
    let mainUser = await User.findOne({ username: req.decoded.username }); 
    if(mainUser && mainUser.branch_id && mainUser.branch_id === '111') {
     permit = mainUser.branch_id;
     // here you add your condiion for (this.request_status == "approved" && this.chapter_id == permit).
     let bloodRequestData = await  Bloodrequest.findOne({ patient_name: req.decoded.patient_name });
     res.json({ success: true, bloodrequests: bloodRequestData }); 
    } 
   } catch (error) {
    throw error
  }
}

据我了解，您尚未在代码中使用User.find({})和Bloodrequest.find({})数据。

如何从另一个函数将值存储到var

2 个答案: