Mastering Schema and Model Definition in TypeScript: A Beginner's Guide

Defining a Schema and Model in TypeScript (with Example)

When working with TypeScript and MongoDB (using Mongoose), defining schemas and models involves leveraging TypeScript interfaces and Mongoose schema definitions. Here’s a step-by-step guide with an example:

• Install Required Packages

Ensure you have Mongoose and TypeScript installed in your project:

npm install mongoose npm install --save-dev @types/mongoose

• Define a TypeScript Interface

The interface describes the structure of your documents.

types/User.ts

export interface IUser { name: string; email: string; age: number; }

• Create a Mongoose Schema

Use the interface to help guide your schema design.

models/User.ts
import { Schema, model } from "mongoose";
import { IUser } from "../types/User";

const UserSchema = new Schema({ name: { type: String, required: true }, email: { type: String, required: true, unique: true }, age: { type: Number, required: true }, });

export const UserModel = model("User", UserSchema);

• Use the Model in Your Code

Now, you can use the UserModel to interact with the database.

index.ts import mongoose from "mongoose";
import { UserModel } from "./models/User";

async function main() {

// Connect to MongoDB await mongoose.connect("mongodb://localhost:27017/mydb");

// Create a new user
const newUser = new UserModel({ name: "Alice", email: "[e-mail]", age: 25, });

// Save the user to the database await newUser.save(); console.log("User saved:", newUser);

// Find all users
const users = await UserModel.find(); console.log("All Users:", users);

// Close the connection
await mongoose.disconnect(); } main().catch((err) => console.error(err));