Simple Prisma DTO Gen

Prisma generator focused on NestJS projects.

It generates:

• DTO classes for Prisma models
• Insert DTO classes
• Enum files
• A DatabaseGenService with CRUD helpers
• An optional PrismaService
• A model.json file with the Prisma DMMF

Scope

This package is not a generic Prisma code generator.

Current assumptions:

• DTOs import @nestjs/swagger
• The optional generated PrismaService imports @nestjs/common
• The optional generated PrismaService uses @prisma/adapter-mariadb (or @prisma/adapter-postgresql)
• The generated service layer is designed for NestJS-style usage

Because of that, the package fits best in NestJS + Prisma projects.

Generated Output

Given an output directory, the generator creates:

<output>/
  dtos/
  insert.dtos/
  enums/
  service/
    database.gen.ts
    prisma.service.ts   # only when generatePrismaService = true
  model.json

Installation

Install the generator and Prisma:

npm install --save-dev prisma @custom-generators/simple-prisma-dto-gen
npm install --save @prisma/client @nestjs/swagger

Install these only if you want the generated PrismaService:

npm install --save @nestjs/common @prisma/adapter-mariadb mariadb dotenv

or

npm install --save @nestjs/common @prisma/adapter-postgresql dotenv

Prisma Schema Configuration

Example schema.prisma:

generator client {
  provider   = "prisma-client"
  output     = "../src/generated/prisma"
  engineType = "library"
}

generator classGenerator {
  provider                     = "npx simple-prisma-dto-gen"
  output                       = "../src/gen.dto"
  customPrismaClientImportPath = "src/generated/prisma/client"
  generatePrismaService        = true
  activeField                  = "active"
}

If you use Postgresql add :

databaseType = "postgresql"

Generator Options

• output: target directory for generated files
• customPrismaClientImportPath: import path used in generated service files
• generatePrismaService: when true, generates service/prisma.service.ts; when false, DatabaseGenService depends directly on PrismaClient
• activeField: when set, generated findOne* and findMany* methods filter by this field set to true, and generated delete* methods perform soft delete by setting this field to false

If activeField is not configured, generated delete* methods call Prisma delete().

Usage

Initialize Prisma if needed:

npx prisma init

Configure your database connection, then introspect or maintain your schema as usual:

npx prisma db pull

Run generators:

npx prisma generate

The provider value must be an executable command that Prisma can run. For this package, use the published bin command, not the npm package name. Using @custom-generators/simple-prisma-dto-gen directly will fail because Prisma tries to execute that exact string in the shell.

If you prefer, you can still use the explicit executable path as a fallback:

generator classGenerator {
  provider = "node node_modules/@custom-generators/simple-prisma-dto-gen/dist/bin.js"
}

NestJS Integration

If you generate PrismaService, load environment variables before the Nest app bootstraps:

import 'dotenv/config'

Example wrapper service:

import { Injectable } from "@nestjs/common"
import { DatabaseGenService } from "./gen.dto/service/database.gen"
import { PrismaService } from "./gen.dto/service/prisma.service"

@Injectable()
export class DatabaseService extends DatabaseGenService {
  constructor(prisma: PrismaService) {
    super(prisma)
  }
}

Register services in your module:

providers: [DatabaseService, PrismaService]

Example

For a Prisma model like:

model User {
  id    Int    @id @default(autoincrement())
  nome  String
  ativo Boolean @default(true)
}

The generator will produce files similar to:

• dtos/user.dto.ts
• insert.dtos/user.insert.dto.ts
• service/database.gen.ts

And DatabaseGenService will include methods like:

• findOneUser
• findManyUser
• createUser
• updateUser
• deleteUser

Limitations

• The generated DTOs are tailored to NestJS Swagger usage
• This package is intentionally opinionated and project-style driven