从mongodb中的嵌套文档数组中删除单个记录

Question

I want to delete just one contact from the contacts array of a particular user from mongdb dynamically using nodejs

    {
    _id:ObjectId("532737785878v7676747788"),
    firstname:"Mark",
    lastname:"Anthony",
    email:"xyz@gmail.com",
    contacts:[
   {
    _id:ObjectId("678758478fr7889889)",
    firstName:"James",
    lastName:"Cole",
    phoneNo:"09746"
   },
  {
    _id:ObjectId("678758478fr7889889)"
    firstName:"Jane"
    lastName:"Doe"
    phoneNo:"12345"
   }
]
    }

I tried this:

       User.updateOne(
       {email:'xyz@gmail.com', 'contacts._id':678758478fr7889889},
       { $pull : { contacts : { firstName:'Jane', lastName:'Doe',  phoneNo:'12345'} } },
       {multi:true},
       );

I am not getting any error messages and it's not deleting any contact

Answer 1

Mongoose would use defined schema to create ObjectId's in DB while on writes but it would not use schema on _id(ObjectId's) for find queries, So you've to explicitly say that _id is an ObjectId(). Please have this in your code :

const mongoose = require('mongoose'); // Ignore this if you've already imported.
const ObjectId = mongoose.Types.ObjectId;

// Assuming id is the value you've got in request.
User.updateOne(
   {email:'xyz@gmail.com', 'contacts._id':new ObjectId(id)},
   { $pull : { contacts : { firstName:'Jane', lastName:'Doe',  phoneNo:'12345'} } });


// you can do the same with `findOneAndUpdate` with options {new: true} which would return updated document, by default it would be false that meant to return old document.
User.findOneAndUpdate(
       {email:'xyz@gmail.com', 'contacts._id':new ObjectId(id)},
       { $pull : { contacts : { firstName:'Jane', lastName:'Doe',  phoneNo:'12345'} } }, {new : true});

Answer 2

db.collection.update({
        email:'xyz@gmail.com',
        contacts: {
            $elemMatch: {
                "_id": "678758478fr7889889"
            }
        }
    }, {
        $pull: {
            contacts: {
                _id: '678758478fr7889889'
            }
        }
    }

)