Duplication between prisma schema and models

[Skona27]

Hi!
First of all thanks for this starter. It is really awesome 😃

I've noticed that some of the code is duplicated between prisma schema definitions and nest js models.
In prisma.schema we have a User definition, which looks like below:

model User {
  id        String   @id @default(cuid())
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
  email     String   @unique
  password  String
  firstname String?
  lastname  String?
  posts     Post[]
  role      Role
}

And also in user.model we define the same 'shape' but with typescript:

@ObjectType()
export class User extends BaseModel {
  email: string;
  firstname?: string;
  lastname?: string;
  role: Role;
  @HideField()
  password: string;
}

Why is that necessary? Can't we somehow generate schema from models, or other way around?

[marcjulian]

@Skona27 Hi, thanks 👍 I hope I can answer your question.

Yes currently the code requires duplicates between the prisma schema and the graphql schema.

1. Database schema: schema.prisma describes the model and thus the table created for this model.
2. GraphQL schema: user.model.ts and any other models describes the response value of your user type for your GraphQL queries

How to resolve the duplicates for now?
It is currently necessary to have duplicate code once in schema.prisma and once for your GraphQL schema.

One idea would be to implement User from prisma client for your graphql model to always keep those prisma and graphql models in sync.

import { User } from '@prisma/client'; 
import { PostModel } from '../post/post.model.ts';

@ObjectType('User')
export class UserModel extends BaseModel implements User {
  email: string;
  @Field({ nullable: true })
  firstname: string;
  @Field({ nullable: true })
  lastname: string;
  role: Role;
  @HideField()
  password: string;
  posts: PostModel[];
}

Another option might be in the feature typegraphql-prisma

And in the near feature - when Prisma SDK will be ready - the typegraphql-prisma integration will also allow to use a code-first approach to build a schema.prisma and GraphQL schema at once, using classes with decorators as a single source of truth. Stay tuned! 💪

There is also an typegraphql integration for nestjs typegraphql-nestjs with some caveats.

[Skona27]

@marcjulian
Thanks for that answer! Everything is clear now