How update a specific value on mongodb database using CRUD operation?

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• How to projection fields for a dictionary (C#, MongdoDB)

  I am trying my luck here, I have a model which is like the following

  public class RowData : BaseBsonDefinition
  {
  .
    [BsonExtraElements]
    [BsonDictionaryOptions(DictionaryRepresentation.ArrayOfDocuments)]
    public Dictionary<string, object> Rows { get; set; } = new(StringComparer.OrdinalIgnoreCase);
  .
  }
  
  

  In result, the schema in the MongoDB looks like

  {
  "_id": {
      "$binary": {
        "base64": "HiuI1sgyT0OZmcgGUit2dw==",
        "subType": "03"
      }
    },
    "c1": "AAA",
    "c8": "Fully Vac",
    "c10": "",
  }
  

  Those c1, c8 and c10 fields are keys from the dictionary, my question is how to dynamic project those fields?

  I tried

  Builders<RowData>.Projection.Exclude(p => "c1")
  

  It seems the MongoDB driver can not handle a value directly.

  Anyone could point me in the correct direction?

  Thanks,
• Error message : MongoServerError: bad auth :Authentication failed

  What is the reason behind this error? this code I am using to connect to DB.

  const uri =`mongodb+srv://${process.env.DB_USER}:${process.env.DB_PASSWORD}@cluster0.xft2s.mongodb.net/myFirstDatabase?retryWrites=true&w=majority`;
  
• In Mongo, If a document I'm saving "Prateek" then I don't want on the next create operation even the "prateek" or "praTEEK", etc is saved

  //** If I'm adding a new document with the name: "India", then I don't want that the DB allow another name with the name: "INDIA", "india", "indIA", etc. I'm new and learning, help would be great!!**

  // Controller

  var Dinosaur = require('../models/dinosaurs');
  
  //addDino
  module.exports.addDino = (req, res) => {
      var name = req.body.name;
      var type = req.body.type;
      var height = req.body.height;
      var weight = req.body.weight;
      var Period = req.body.Period;
  
      req.checkBody('name', 'Name is required').notEmpty();
  
      var errors = req.validationErrors();
      if (errors)
          return res.status(400).send({
              message: 'Name is Required'
          });
      else {
          let newDino = {
              name: name,
              type: type,
              height: height,
              weight: weight,
              Period: Period
          }
          Dinosaur.addDino(newDino, (err, result) => {
              if (err) {
                  if (err.name) return res.status(409).send({
                      message: name + ' Already Exist'
                  });
                  else if (err.url) return res.json({ status: false, error: { url: "Url already exist" }, message: err.url });
                  else return res.json(err, "Server Error");
              }
              else {
                  return res.status(200).send({
                      message: "Done"
                  });
              }
          });
      }
  }
  

  // Model

  var mongoose = require('mongoose');
  
  //dinosaur schema
  var DinosaurSchema = mongoose.Schema({
      name: {
          type: String,
          unique: true
      },
      type: {
          type: String
      },
      height: {
          type: Number
      },
      weight: {
          type: Number
      },
      Period: {
          type: String
      }
  });
  
  var Dinosaur = mongoose.model('dinosaur', DinosaurSchema);
  
  //add
  module.exports.addDino = (query, callback) => {
      Dinosaur.create(query, callback);
  }
  

  // GetAll, Already Created a new document with the name "Brachiosaurus"

  

  // > Create, a new create with the first letter lower case "brachiosaurus", Don't want it to be pushed.

  //Get All, Got pushed.
• How to send query with variables from Rstudio to Mongo database?

  I'm trying to send query to my Mongo database depending on a variable producted in my R code. Unfortunately, Mongo query needs double quotes and the function "paste" in R doesn't support it. Here my variable is equal to "test01" but it will change at each iteration. I tried to build a great character chain named "req" thanks to some "paste" functions with returns:

  req
  > "'{\"id\":\"test01\"}'"
  cat(req)
  > '{"id":"test01"}'

  Which seems to be as a query but when I try :

  connection_db$count(jsonlite::toJSON(req))

  It returns [0] whereas if if try :

  connection_db$count('{"id":"test01"}')

  It returns [1]. Can you help me please?