Mongoose advanced in MongoDB

🔹 What are Discriminators? Discriminators allow you to store different types of documents in the same collection using a base schema. 👉 Think of it like: One collection Multiple document types 📌 Used when documents are similar but have some different fields 🔹 Why Use Discriminators? Avoid creating multiple collections Reuse common fields Keep data organized 🔹 Basic Idea You create: Base Schema (common fields) Child Schemas (extra fields) 🔹 Example 👉 Base Schema (Vehicle) const mongoose = require("mongoose") const options = { discriminatorKey: "type" } const vehicleSchema = new mongoose.Schema({ brand: String }, options) const Vehicle = mongoose.model("Vehicle", vehicleSchema) 👉 Child Schema (Car) const carSchema = new mongoose.Schema({ doors: Number }) const Car = Vehicle.discriminator("Car", carSchema) 👉 Child Schema (Bike) const bikeSchema = new mongoose.Schema({ hasCarrier: Boolean }) const Bike = Vehicle.discriminator("Bike", bikeSchema) 🔹 How Data Looks in DB All stored in same collection (vehicles) : Document 1: type: "Car", brand: "Toyota", doors: 4 Document 2: type: "Bike", brand: "Hero", hasCarrier: true 🔹 discriminatorKey 👉 Field that tells which type of document it is Example: type: "Car" or "Bike" (Default key is __t if not specified) 🔹 When to Use Use discriminators when: Data shares common structure But has some differences 📌 Examples: Payment methods (card, UPI, cash) Vehicles (car, bike) Users (admin, customer) 🔥 Simple Understanding 👉 One collection + multiple document types 👉 Shared base + specific fields