user.js

const mongoose = require("mongoose");

main().catch((err) => console.log(err));

async function main() {
  await mongoose.connect("mongodb://localhost:27017/hardik");
  const userSchema = new mongoose.Schema({
    name: String,
    age: Number,
    // email: {
    //   //when you field to be required or want it to be lowercase
    //   type: String,
    //   required: true,
    //   lowercase: true,
    // },
  });
  const User = mongoose.model("User", userSchema);
  const user = new User({ name: "hardik", age: 28 });
  const user2 = await User.create({ name: "tikul", age: 29 }); //another way of adding user with saving
  // user.name = "HARDIK"; //for updating
  user2.name = "Tikul";
  // User.email = "hardik@gmail.com";
  await user2.save(); //we have to save this time because of update.
  await user.save();
  console.log(user);
  console.log(user2);

  const filter = { name: "hardik" };
  const update = { age: 30 };
  let doc = await User.findOneAndUpdate(filter, update, {
    new: true,
  });
  console.log(doc);
}