how do i delete array item in mongodb?-CodePudding

I want to delete an element according to the value of "noteID" from the note array inside the project schema in mongo db.

Project Schema

  endDate: {
    type: String,
    required: true,
    default: Date.now().toString()
  },
  notes: {
    type: [NoteSchema],
    required: false
  },
  users: [{
    type: String,
    required: false
  }]

Note Schema

const NoteSchema = mongoose.Schema({
  noteID: {
    type: String,
    require: true
  },
  title: {
    type: String,
    required: true
  },
  description: {
    type: String,
    required: true
  },
  endDate: {
    type: Date,
    default: Date.now()
  },
  priority: {
    type: String,
    default: "low"
  }
});

returning json with express

"endDate": "11.11.2021",
                "notes": [
                    {
                        "endDate": "2022-02-05T08:02:18.166Z",
                        "priority": "low",
                        "_id": "61fe2f423667ad054b62f84f",
                        "noteID": "cb978ec0-7229-4253-9e36-eaaf85b72ae3",
                        "title": "test note title",
                        "description": "test note desc"
                    },
                    {
                        "endDate": "2022-02-05T08:02:18.166Z",
                        "priority": "medium",
                        "_id": "61fe2f593667ad054b62f851",
                        "noteID": "760fda9f-e453-4e9c-bc9f-161f38fd29c0",
                        "title": "test note title 2",
                        "description": "test note desc 2"
                    }
                ],
                "users": [],

I want to delete an item from this notes directory using noteID.

CodePudding user response：

Basically you can delete a schema item like that in mongoose.

YourColletionName.findOneAndDelete({ noteID: "cb978ec0-7229-4253-9e36-eaaf85b72ae3" },
  function (err, data) {

    if (err){
      console.log(err)
    }
    else{
      console.log("Removed: ", data);
  }

});

If you want to delete with the noteID link on your page you can use req.params.noteID instead of cb978ec0-7229-4253-9e36-eaaf85b72ae3.

Resources:

CodePudding user response：

Use update with $pull to remove the element from the array by noteID:

  db.collection.update({},
 {
   $pull: {
      notes: {
        noteID: "cb978ec0-7229-4253-9e36-eaaf85b72ae3"
   }
  }
 })

Explained:

The above query will remove all objects with nodeID: "cb978ec0-7229-4253-9e36-eaaf85b72ae3" from the array of objects notes[]. The operation apply to the first found document in collection. If you need to apply to all documents in collections you need to add the { multi:true } option

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