如何在node.js中用monk更新mongodb中的嵌套字段

Question

我正在用新記錄更新MongoDB數據庫。數據庫由數組組成的練習字段組成，當我做PUT頭時，我想用新記錄更新特定練習，不要覆蓋特定練習的整個字段，因爲我想保留進度的歷史記錄。到目前爲止，我只能獲取在router.get（'/：nickname /：info'）中看到的特定嵌套字段，我們可以在其中指定用戶及其名稱，年齡或性別。我可以在練習場上做同樣的事情，但我一直未能更新這些練習場。這裏的數據庫：

[ 
{ 
    "_id": "59283956c52a5420e74966b9", 
    "info": { 
     "nickname": "annwumy", 
     "name": "Bert", 
     "gender": "male", 
     "age": 25 
    }, 
    "exercises": [ 
     { 
     "exercise": { 
      "name": "squats", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "legpresses", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "deadlifts", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "benchpresses", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "pullups", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "shoulderpress", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "curls", 
      "records": [] 
     } 
     } 
    ] 
    }, 
    { 
    "_id": "5928397fc52a5420e74966ba", 
    "info": { 
     "nickname": "mmsmsy", 
     "name": "Mateusz", 
     "gender": "male", 
     "age": 26 
    }, 
    "exercises": [ 
     { 
     "exercise": { 
      "name": "squats", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "legpresses", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "deadlifts", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "benchpresses", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "pullups", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "shoulderpress", 
      "records": [] 
     } 
     }, 
     { 
     "exercise": { 
      "name": "curls", 
      "records": [] 
     } 
     } 
    ] 
    } 
] 

而這裏的後端代碼的請求：

const express = require('express'); 
const router = express.Router(); 
const app = express(); 
const cors = require('cors'); 
const bodyParser = require('body-parser'); 
const axios = require('axios'); 

const monk = require('monk'); 
const db = require('monk')('localhost/fitness-log'); 
const users = db.get('users'); 

app.use(cors()); 
app.use(bodyParser.json()); 
app.use(bodyParser.urlencoded({extended: true})); 

app.use('/api/v1', router); 


router.get('/listusers', (req, res) => { 
    users.find() 
    .then(users => res.json(users)) 
}); 

router.get('/users/:id', (req, res) => { 
    users.find({'_id': req.params.id}) 
    .then(user => res.json(user[0])) 
}); 

router.get('/:nickname/:info', (req, res) => { 
    users.find({'nickname': req.params.nickname}, `info.${req.params.info}`) 
    .then(user => res.json(user[0])) 
}); 

router.post('/adduser', (req, res) => { 
    users.insert(req.body, (err, result) => { 
    res.send(
     (err === null) ? { msg: result } : { msg: err } 
    ); 
    }); 
}); 

router.put('/updateinfo/:nickname/:info', (req, res) => { 
    const updateQuery = {$set: {}}; 
    updateQuery.$set[`info.${req.params.info}`] = req.body.value; 
    users.update({'nickname': req.params.nickname}, updateQuery, (err, result) => { 
    res.send(
     (err === null) ? { msg: result } : { msg: err } 
    ); 
    }); 
}); 

router.put('/addrecord/:nickname/:exercise', (req, res) => { 
    const updateQuery = {$push: {}}; 
    updateQuery.$push[`exercises.${req.params.exercise}`] = req.body; 
    users.update({'nickname': req.params.nickname}, updateQuery, (err, result) => { 
    res.send(
     (err === null) ? { msg: result } : { msg: err } 
    ); 
    }); 
}); 

router.delete('/deleteuser/:nickname', (req, res) => { 
    users.remove({ 'nickname': req.params.nickname }, err => { 
    res.send((err === null) ? { msg: '' } : { msg: 'error: ' + err}); 
    }); 
}); 

router.delete('/deleteallusers', (req, res) => { 
    users.remove({}, err => { 
    res.send(err === null) ? {msg: '' } : { msg: 'error: ' + err}; 
    }); 
}); 

app.listen(3001,() => console.log("Server running at 3001")); 

Answer 1

bug是在更新表達式：

{$set: `info.${req.params.info}`} 

它必須是：

const updateQuery = {$set: {}}; 
updateQuery.$set[`info.${req.params.info}`] = req.params.infoValue; 
users.update({'nickname': req.params.nickname}, updateQuery, (err, result) => {