如何将键/值对数组更新为猫鼬？

Question

Background: I have an array of objects sent from Vue Axios. These objects are key value pairs which is stored in the req.body.

Req.body

keyValue:  [{key:"some key", value:"some value"}, {key:"some key2", value:"some value2"}]

Note : I can expect to receive a req.body with a numerous amount objects withing the array. I can not access the "key" and "value" in the objects without adding a [ ] or req.body.keyValue[0].

How can I dynamically add each object's "key" and "value" into mongoose without having to explicitly call a specific object?

I am trying to do something like this: (failed attempt)

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const Schema = new Schema({
  Pair: [{
    Key: String,
    Value: Number
  }]
});

router.post("/",  (req, res) => {
 User.update({},
  {$push:
  {Pair:{
        Key: req.body.keyValue.key,
         Value: req.body.keyValue.value
       }
      }
    }, 
  (err,result)=>{
    if(err){
      console.log(err);
      res.status(400).send('Error')
    }else{
      res.status(200).send(result);
    }
  })
}

I hope I was able to explain well enough. Let me know if there is any confusions. Thanks!

Answer 1

User Schema

userId: {
    type: String
},
password: {
    type: String
},
friends: [{
    userId: String,
    followSent: Boolean,
    followAccepted: Boolean,
    followbackSent: Boolean,
    followbackAccepted: Boolean,
    inchats: Boolean
}]

Update Code

userModel.updateOne({ userId: "MyId" , "friends.userId": "frndId"},{
$set: {
        'friends.$.followSent': true}},(err, docs) => {
                   
        })

Answer 2

The point here is that when your call req.body.keyValue.key and req.body.keyValue.value , they are in a javascript array req.body.keyValue[] .

Presuming that the req.body.keyValue will be always a valid array with the { key: '...', value: '...' } you can use the MongoDB $each operator to update your document.

As:

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const Schema = new Schema({
  Pair: [{
    key: String,
    value: Number
  }]
});

router.post("/",  (req, res) => {
  User.update(
    {},
    {
      $push: {
        Pair:{
          $each : req.body.keyValue
        }
      }
    }, 
    (err,result)=>{
      if(err){
        console.log(err);
        res.status(400).send('Error')
      }else{
        res.status(200).send(result);
      }
    }
  );
}

Now just be careful that req.body.keyValue has the right capitalization on each element, so you don't have *K*ey and/or *k*ey , that will not match your schema. =]

Edit

Just to explain how the $each operator will work, see the following example:

req.body = {
  keyValue : [
    { key : "key1", value : 1 },
    { key : "key2", value : 2 }
  ]
};

Document in User collection before the update:

{
  _id : ObjectId(),
  Pair : [
    { key : "key_A", value : 99 }
  ]
}

After the .update() with the $each operator, the expected updated document:

{
  _id : ObjectId(),
  Pair : [
    { key : "key_A", value : 99 },
    { key : "key1", value : 1 },
    { key : "key2", value : 2 }
  ]
}