How can i use TypeORM with better- sqlite3

Using TypeORM to interact with SQLite databases is a relatively straightforward process. Below are some basic steps and examples to guide you through the process.

Step 1: Install TypeORM and SQLite3

First, install TypeORM and SQLite3 in your Node.js project. If you haven't initialized a project yet, use npm init to create a new one. Then run the following commands:

bash
npm install typeorm sqlite3 reflect-metadata

reflect-metadata is a dependency required by TypeORM for decorators.

Step 2: Configure TypeORM

Create a configuration file named ormconfig.json in the root directory of your project, specifying the following SQLite database configuration:

json
{
   "type": "sqlite",
   "database": "database.sqlite",
   "entities": ["src/entity/**/*.ts"],
   "synchronize": true,
   "logging": false
}

The "entities" path should point to the directory containing your entity classes.

Step 3: Define Entities

Defining entity classes models the tables in the database. Create an entity class file User.ts as an example:

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

@Entity()
export class User {

    @PrimaryGeneratedColumn()
    id: number;

    @Column()
    firstName: string;

    @Column()
    lastName: string;

    @Column()
    age: number;
}

Step 4: Connect to the Database and Perform Operations

Next, create a script to establish a database connection and perform CRUD operations. In your index.ts (or other entry point file), use the following code to connect to the database and execute operations:

typescript
import "reflect-metadata";
import { createConnection } from "typeorm";
import { User } from "./entity/User";

createConnection().then(async connection => {

    console.log("Inserting a new user into the database...");
    const user = new User();
    user.firstName = "Timber";
    user.lastName = "Saw";
    user.age = 25;

    await connection.manager.save(user);
    console.log("Saved a new user with id: " + user.id);

    console.log("Loading users from the database...");
    const users = await connection.manager.find(User);
    console.log("Loaded users: ", users);

    console.log("Here you can setup and run express/koa/any other framework.");

}).catch(error => console.log(error));

In this code, we first establish a connection, insert a new user, query all users, and print the results.

Step 5: Run the Project

After completing the above steps, run your Node.js application. If your entry file is index.ts, execute it with the following command:

bash
npx ts-node src/index.ts

Ensure you have installed ts-node to run TypeScript files.

Summary

This outlines the basic steps for working with TypeORM and SQLite databases. TypeORM is a powerful ORM that simplifies interaction with SQLite (and many other databases) and provides rich decorators and methods for managing your data models and database operations.