What is TypeORM? A Beginner's Guide

TypeORM is an object-relational mapping (ORM) library used in Node.js and Typescript projects. With TypeORM, working with databases becomes modern and time-saving. In applications running on JavaScript or TypeScript, it allows you to manage your database operations with more readable and sustainable code. It is especially widely used in scalable projects and enterprise applications.

Project Setup with TypeORM

To start using TypeORM, you first need a Node.js project. Then, TypeORM and a database driver (such as PostgreSQL, MySQL, SQLite) are added to your project via npm. TypeORM is very strong with both active development and community support.

Installation and Simple Usage Example

The example below shows a TypeORM setup with PostgreSQL and a basic entity definition:

npm install typeorm reflect-metadata pg

Entity file:

import { Entity, PrimaryGeneratedColumn, Column } from "typeorm";

@Entity()
export class User {
  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  name: string;
}

Basic connection example:

import "reflect-metadata";
import { DataSource } from "typeorm";
import { User } from "./User";

const AppDataSource = new DataSource({
  type: "postgres",
  host: "localhost",
  port: 5432,
  username: "postgres",
  password: "password",
  database: "test_db",
  synchronize: true,
  logging: false,
  entities: [User],
});

AppDataSource.initialize()
  .then(async () => {
    const user = new User();
    user.name = "Mehmet";
    await AppDataSource.manager.save(user);
    console.log("User saved.");
  })
  .catch(error => console.log(error));

Advantages and Use Cases

TypeORM reduces code duplication with object-based data modeling and automatic query generation, while increasing code readability and maintainability. The clearest answer to the question What is TypeORM? is that it is an ORM solution that enables projects to manage their databases in a modern and secure way. It supports many advanced features such as migration, repository pattern, lazy/eager loading. It is preferred in a wide range of projects from small projects to the largest enterprise applications.

Conclusion

The answer to the question What is TypeORM? is that it is a flexible and modular ORM tool that offers great convenience especially for developers creating data-intensive applications. From beginner to advanced level projects, you can perform your database operations safely and quickly with TypeORM. You can review advanced techniques for TypeORM through the official documentation.