NestJS + Prisma/TypeORM

Q: How do I test services with Prisma?

Mock PrismaService with overrideProvider, or use a test database with prisma migrate reset.

Q: Should entities be in the same module as controllers?

Separate entities/ or prisma/ from controllers. Services bridge the gap.

Q: How do I handle database migrations in CI?

Run prisma migrate deploy or TypeORM migrations in deploy pipeline before starting the app.

Integrate Prisma or TypeORM as the data layer in NestJS 11 with proper DI, lifecycle, and testing patterns.

Recipe

Quick-reference recipe card - copy-paste ready.

Prisma:

import { Injectable, OnModuleInit, OnModuleDestroy } from "@nestjs/common";
import { PrismaClient } from "@prisma/client";
 
@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
  async onModuleInit() { await this.$connect(); }
  async onModuleDestroy() { await this.$disconnect(); }
}
 
@Injectable()
export class UsersService {
  constructor(private prisma: PrismaService) {}
  findAll() { return this.prisma.user.findMany(); }
}

When to reach for this: Any NestJS API that needs a database. Prisma for DX and migrations; TypeORM for decorator-driven entities.

Working Example

Prisma Module

// prisma.module.ts
import { Global, Module } from "@nestjs/common";
import { PrismaService } from "./prisma.service.js";
 
@Global()
@Module({
  providers: [PrismaService],
  exports: [PrismaService],
})
export class PrismaModule {}
 
// users.service.ts
import { Injectable } from "@nestjs/common";
import { PrismaService } from "../prisma/prisma.service.js";
 
@Injectable()
export class UsersService {
  constructor(private prisma: PrismaService) {}
 
  async findById(id: string) {
    return this.prisma.user.findUnique({ where: { id } });
  }
 
  async create(data: { name: string; email: string }) {
    return this.prisma.user.create({ data });
  }
}
 
// Test override
const mockPrisma = {
  user: {
    findUnique: async () => ({ id: "1", name: "Test", email: "t@t.com" }),
    create: async (args: { data: { name: string; email: string } }) => ({ id: "1", ...args.data }),
  },
};

TypeORM Module

import { Module } from "@nestjs/common";
import { TypeOrmModule } from "@nestjs/typeorm";
import { User } from "./user.entity.js";
import { UsersService } from "./users.service.js";
 
@Module({
  imports: [TypeOrmModule.forFeature([User])],
  providers: [UsersService],
  exports: [UsersService],
})
export class UsersModule {}
 
@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(User) private repo: Repository<User>,
  ) {}
 
  findAll() { return this.repo.find(); }
}

What this demonstrates:

PrismaService with connect/disconnect lifecycle
Global PrismaModule for app-wide injection
TypeORM forFeature for entity-scoped repositories
Mock Prisma client for unit tests

Deep Dive

Prisma vs TypeORM in NestJS

Factor	Prisma	TypeORM
Schema definition	`schema.prisma` file	Decorator entities
Migrations	`prisma migrate`	TypeORM migrations
Query style	Generated client API	Repository / QueryBuilder
NestJS integration	Manual service wrapper	`@nestjs/typeorm` module
Raw SQL	`$queryRaw`	QueryBuilder raw
Team preference	DX-focused teams	Decorator/Spring-like teams

Transaction Pattern (Prisma)

async transfer(fromId: string, toId: string, amount: number) {
  return this.prisma.$transaction(async (tx) => {
    await tx.account.update({ where: { id: fromId }, data: { balance: { decrement: amount } } });
    await tx.account.update({ where: { id: toId }, data: { balance: { increment: amount } } });
  });
}

Repository Pattern

Keep controllers thin; services call Prisma or repositories. See Repository Pattern.

Gotchas

PrismaService not disconnected - connection pool leaks on shutdown. Fix: implement onModuleDestroy.
Prisma in request scope - unnecessary overhead. Fix: singleton PrismaService, pass tenant ID as parameter.
TypeORM synchronize: true in production - auto-alters schema dangerously. Fix: use migrations only.
N+1 queries in services - Prisma include forgotten. Fix: use include/select or DataLoader.
Testing against real database - slow, flaky tests. Fix: mock PrismaService or use Testcontainers.
Global module for everything - hides dependencies. Fix: global only for Prisma/Config; feature modules explicit.

Alternatives

Alternative	Use When	Don't Use When
Prisma	Type-safe client, easy migrations	Heavy raw SQL, existing TypeORM codebase
TypeORM	Decorator entities, NestJS native module	Want Prisma-level DX
Drizzle ORM	Lightweight, SQL-first	Need mature NestJS integration
Raw pg driver	Maximum control	Standard CRUD API

FAQs

Should PrismaModule be global?

Common pattern for singleton PrismaService. Alternative: import PrismaModule in each feature module for explicit deps.

How do I handle Prisma in serverless?

Connection pooling via Prisma Accelerate or PgBouncer. Avoid per-invocation $connect without pooling.

Can I use both Prisma and TypeORM?

Technically yes, practically avoid it. Pick one ORM per service.

How do I test services with Prisma?

Mock PrismaService with overrideProvider, or use a test database with prisma migrate reset.

How does this work with NestJS microservices?

Same PrismaService injected into message handlers. One DB connection pool per process.

Should entities be in the same module as controllers?

Separate entities/ or prisma/ from controllers. Services bridge the gap.

How do I handle database migrations in CI?

Run prisma migrate deploy or TypeORM migrations in deploy pipeline before starting the app.

What about read replicas?

Prisma supports read replicas via extension. TypeORM supports multiple connections in config.

NestJS Basics - module structure
Dependency Injection - service wiring
Repository Pattern - data access layer
Databases - database fundamentals
NestJS Best Practices - section checklist

NestJS Documentation - Progressive Node.js framework docs.
Node.js Best Practices (GitHub) - Curated production best practices.
DigitalOcean Node.js Tutorials - Production-oriented how-tos.
Node.js Cookbook, 5th Edition - Practical server-side recipes.
Node.js Design Patterns, 4th Edition - Production-grade application patterns.

Stack versions: This page was written for Node.js 24.18.0 (Active LTS), npm 10+, TypeScript 5.6+, Express 5, Fastify 5, and NestJS 11.

Recipe

Quick-reference recipe card - copy-paste ready.

Prisma:

import { Injectable, OnModuleInit, OnModuleDestroy } from "@nestjs/common";
import { PrismaClient } from "@prisma/client";
 
@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
  async onModuleInit() { await this.$connect(); }
  async onModuleDestroy() { await this.$disconnect(); }
}
 
@Injectable()
export class UsersService {
  constructor(private prisma: PrismaService) {}
  findAll() { return this.prisma.user.findMany(); }
}

When to reach for this: Any NestJS API that needs a database. Prisma for DX and migrations; TypeORM for decorator-driven entities.

Working Example

Prisma Module

// prisma.module.ts
import { Global, Module } from "@nestjs/common";
import { PrismaService } from "./prisma.service.js";
 
@Global()
@Module({
  providers: [PrismaService],
  exports: [PrismaService],
})
export class PrismaModule {}
 
// users.service.ts
import { Injectable } from "@nestjs/common";
import { PrismaService } from "../prisma/prisma.service.js";
 
@Injectable()
export class UsersService {
  constructor(private prisma: PrismaService) {}
 
  async findById(id: string) {
    return this.prisma.user.findUnique({ where: { id } });
  }
 
  async create(data: { name: string; email: string }) {
    return this.prisma.user.create({ data });
  }
}
 
// Test override
const mockPrisma = {
  user: {
    findUnique: async () => ({ id: "1", name: "Test", email: "t@t.com" }),
    create: async (args: { data: { name: string; email: string } }) => ({ id: "1", ...args.data }),
  },
};

TypeORM Module

import { Module } from "@nestjs/common";
import { TypeOrmModule } from "@nestjs/typeorm";
import { User } from "./user.entity.js";
import { UsersService } from "./users.service.js";
 
@Module({
  imports: [TypeOrmModule.forFeature([User])],
  providers: [UsersService],
  exports: [UsersService],
})
export class UsersModule {}
 
@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(User) private repo: Repository<User>,
  ) {}
 
  findAll() { return this.repo.find(); }
}

What this demonstrates:

PrismaService with connect/disconnect lifecycle
Global PrismaModule for app-wide injection
TypeORM forFeature for entity-scoped repositories
Mock Prisma client for unit tests

Deep Dive

Prisma vs TypeORM in NestJS

Factor	Prisma	TypeORM
Schema definition	`schema.prisma` file	Decorator entities
Migrations	`prisma migrate`	TypeORM migrations
Query style	Generated client API	Repository / QueryBuilder
NestJS integration	Manual service wrapper	`@nestjs/typeorm` module
Raw SQL	`$queryRaw`	QueryBuilder raw
Team preference	DX-focused teams	Decorator/Spring-like teams

Transaction Pattern (Prisma)

async transfer(fromId: string, toId: string, amount: number) {
  return this.prisma.$transaction(async (tx) => {
    await tx.account.update({ where: { id: fromId }, data: { balance: { decrement: amount } } });
    await tx.account.update({ where: { id: toId }, data: { balance: { increment: amount } } });
  });
}

Repository Pattern

Keep controllers thin; services call Prisma or repositories. See Repository Pattern.

Gotchas

PrismaService not disconnected - connection pool leaks on shutdown. Fix: implement onModuleDestroy.
Prisma in request scope - unnecessary overhead. Fix: singleton PrismaService, pass tenant ID as parameter.
TypeORM synchronize: true in production - auto-alters schema dangerously. Fix: use migrations only.
N+1 queries in services - Prisma include forgotten. Fix: use include/select or DataLoader.
Testing against real database - slow, flaky tests. Fix: mock PrismaService or use Testcontainers.
Global module for everything - hides dependencies. Fix: global only for Prisma/Config; feature modules explicit.

Alternatives

Alternative	Use When	Don't Use When
Prisma	Type-safe client, easy migrations	Heavy raw SQL, existing TypeORM codebase
TypeORM	Decorator entities, NestJS native module	Want Prisma-level DX
Drizzle ORM	Lightweight, SQL-first	Need mature NestJS integration
Raw pg driver	Maximum control	Standard CRUD API

FAQs

Should PrismaModule be global?

Common pattern for singleton PrismaService. Alternative: import PrismaModule in each feature module for explicit deps.

How do I handle Prisma in serverless?

Connection pooling via Prisma Accelerate or PgBouncer. Avoid per-invocation $connect without pooling.

Can I use both Prisma and TypeORM?

Technically yes, practically avoid it. Pick one ORM per service.

How do I test services with Prisma?

Mock PrismaService with overrideProvider, or use a test database with prisma migrate reset.

How does this work with NestJS microservices?

Same PrismaService injected into message handlers. One DB connection pool per process.

Should entities be in the same module as controllers?

Separate entities/ or prisma/ from controllers. Services bridge the gap.

How do I handle database migrations in CI?

Run prisma migrate deploy or TypeORM migrations in deploy pipeline before starting the app.

What about read replicas?

Prisma supports read replicas via extension. TypeORM supports multiple connections in config.

NestJS Basics - module structure
Dependency Injection - service wiring
Repository Pattern - data access layer
Databases - database fundamentals
NestJS Best Practices - section checklist

NestJS Documentation - Progressive Node.js framework docs.
Node.js Best Practices (GitHub) - Curated production best practices.
DigitalOcean Node.js Tutorials - Production-oriented how-tos.
Node.js Cookbook, 5th Edition - Practical server-side recipes.
Node.js Design Patterns, 4th Edition - Production-grade application patterns.

Stack versions: This page was written for Node.js 24.18.0 (Active LTS), npm 10+, TypeScript 5.6+, Express 5, Fastify 5, and NestJS 11.

NestJS + Prisma/TypeORM

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NestJS + Prisma/TypeORM