Question

我正在尝试读取expressjs中的mongoDB数据并将其返回，但是收到了错误

{
    "error": {
        "message": "Cannot read property 'DiseaseID' of undefined"
    }
}

代码是：

exports.UserDiseaseInfo = (req, res,next) => {

            let retval = {};
            let body = req.body;
            let UId    = (body.UId != undefined) ? body.UId : false;
            let SubDId  = (body.SubDId != undefined) ? body.SubDId: false;

             if(UId==false||SubDId==false){
                             res.status(404).send({response:"Fail", body: req.body});
                          }
             var subd = subDisease_model.findById(SubDId);
                    let data = {
                                            response:'success',
                                            subDisease :  "XX",
                                            diseaseId : subd[0].DiseaseID

                                         }
                     res.status(200).send(data);
};

SubDiseaseModel：

const mongoose = require('mongoose');
const AddictionsSchema = new mongoose.Schema({
    DiseaseID   : mongoose.Schema.Types.String,
    SubDisease  : mongoose.Schema.Types.String
});
module.exports = mongoose.model('SubDiseaseMaster', AddictionsSchema, 'SubDiseaseMaster');

数据库数据：

db.SubDiseaseMaster.find({})
{ "_id" : ObjectId("5ad0850efdcab0ab875c4890"), "DiseaseID" : "5ad06decfdcab0ab875c4838", "SubDisease" : "Acidity" }

JSON致电：

POST /api/UserDiseaseInfo HTTP/1.1
Host: 1nature.in
Content-Type: application/json
Cache-Control: no-cache
Postman-Token: 62e22748-5c30-3f4b-4852-fc0bab68db0d

{
    "UId":"A",
    "SubDId": "5ad0850efdcab0ab875c48a4"
}

知道我哪里失败了？

Answer 1

findById返回单个文档，您将其视为数组并尝试阅读如下：

let data = {
             response:'success',
             subDisease :  "XX",
             diseaseId : subd[0].DiseaseID // <- here is the problem 
}

将subd[0].DiseaseID替换为subd.DiseaseID，问题将得到解决。

无法使用findById

1 个答案: