NestJS Framework with Drizzle ORM

When to Use

• Building REST APIs or GraphQL servers with NestJS
• Setting up authentication and authorization
• Implementing middleware, guards, or interceptors
• Working with databases (TypeORM, Drizzle ORM)
• Creating microservices architecture
• Writing unit and integration tests
• Setting up OpenAPI/Swagger documentation

Core Architecture

Module Structure

import { Module } from '@nestjs/common';

@Module({
  imports: [/* other modules */],
  controllers: [/* controllers */],
  providers: [/* providers */],
  exports: [/* exported providers */],
})
export class FeatureModule {}

Controller Pattern

import { Controller, Get, Post, Body, Param, Query } from '@nestjs/common';

@Controller('users')
export class UsersController {
  @Get()
  findAll(@Query() query: any) {
    return 'This returns all users';
  }

  @Get(':id')
  findOne(@Param('id') id: string) {
    return `This returns user #${id}`;
  }

  @Post()
  create(@Body() createUserDto: any) {
    return 'This creates a user';
  }
}

Service with Dependency Injection

import { Injectable } from '@nestjs/common';

@Injectable()
export class UsersService {
  constructor(/* inject dependencies */) {}

  findAll() {
    return 'Users service logic';
  }
}

Database Integration with Drizzle

Setup with Drizzle ORM

Installation

# Using npm
npm install drizzle-orm pg
npm install -D drizzle-kit tsx @types/pg

# Using yarn
yarn add drizzle-orm pg
yarn add -D drizzle-kit tsx @types/pg

Configuration

// drizzle.config.ts
import 'dotenv/config';
import { defineConfig } from 'drizzle-kit';

export default defineConfig({
  out: './drizzle',
  schema: './src/db/schema.ts',
  dialect: 'postgresql',
  dbCredentials: {
    url: process.env.DATABASE_URL!,
  },
});

Database Schema

// src/db/schema.ts
import { pgTable, serial, text, timestamp } from 'drizzle-orm/pg-core';

export const users = pgTable('users', {
  id: serial('id').primaryKey(),
  name: text('name').notNull(),
  email: text('email').notNull().unique(),
  createdAt: timestamp('created_at').defaultNow(),
});

Database Service

// src/db/database.service.ts
import { Injectable } from '@nestjs/common';
import { drizzle } from 'drizzle-orm/node-postgres';
import { Pool } from 'pg';
import * as schema from './schema';

@Injectable()
export class DatabaseService {
  private db: ReturnType<typeof drizzle>;

  constructor() {
    const pool = new Pool({
      connectionString: process.env.DATABASE_URL,
    });
    this.db = drizzle(pool, { schema });
  }

  get database() {
    return this.db;
  }
}

User Repository with Drizzle

// src/users/user.repository.ts
import { Injectable } from '@nestjs/common';
import { DatabaseService } from '../db/database.service';
import { users } from '../db/schema';
import { eq } from 'drizzle-orm';

@Injectable()
export class UserRepository {
  constructor(private db: DatabaseService) {}

  async findAll() {
    return this.db.database.select().from(users);
  }

  async findOne(id: number) {
    const result = await this.db.database
      .select()
      .from(users)
      .where(eq(users.id, id))
      .limit(1);
    return result[0];
  }

  async create(data: typeof users.$inferInsert) {
    const result = await this.db.database
      .insert(users)
      .values(data)
      .returning();
    return result[0];
  }

  async update(id: number, data: Partial<typeof users.$inferInsert>) {
    const result = await this.db.database
      .update(users)
      .set(data)
      .where(eq(users.id, id))
      .returning();
    return result[0];
  }

  async remove(id: number) {
    const result = await this.db.database
      .delete(users)
      .where(eq(users.id, id))
      .returning();
    return result[0];
  }
}

Complete User Module

// src/users/users.module.ts
import { Module } from '@nestjs/common';
import { UsersController } from './users.controller';
import { UsersService } from './users.service';
import { UserRepository } from './user.repository';
import { DatabaseService } from '../db/database.service';

@Module({
  controllers: [UsersController],
  providers: [UsersService, UserRepository, DatabaseService],
  exports: [UsersService],
})
export class UsersModule {}

User Service Implementation

// src/users/users.service.ts
import { Injectable } from '@nestjs/common';
import { UserRepository } from './user.repository';
import { User } from './interfaces/user.interface';

@Injectable()
export class UsersService {
  constructor(private userRepository: UserRepository) {}

  async findAll(): Promise<User[]> {
    return this.userRepository.findAll();
  }

  async findOne(id: number): Promise<User> {
    const user = await this.userRepository.findOne(id);
    if (!user) {
      throw new Error('User not found');
    }


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