One-sided n:m relations

In Prisma 1, it was possible to have something like

type Translation {
    id: ID! @id
    value: String!
    language: Language!
}
type Post {
    id: ID! @id @unique
    title: [Translation] @relation(name: "PostTitle")
    content: [Translation] @relation(name: "PostContent")
}

if I try something similar with the new prisma2 schema, I am getting

error: Error validating model “Post”: Named relations require an opposite field…

This is what I’ve tried:

model Translation {
    id String @default(cuid()) @id
    value String
    language String
}

model Post {
    id String @id @default(cuid())
    title Translation[] @relation(name: "PostTitle")
    content Translation[] @relation(name: "PostContent")
}

It does work when I add oppsite relationships:

model Translation {
    id String @default(cuid()) @id
    value String
    language String

    ignore1 Post[] @relation("PostTitle")
    ignore2 Post[] @relation("PostContent")
}

model Post {
    id String @id @default(cuid())
    title Translation[] @relation(name: "PostTitle")
    content Translation[] @relation(name: "PostContent")
}

But honestly, I’m not interested in those. Those will just clutter my data model and add methods I do not want to use to my client. Is there any way to avoid that? (Or will it be before prisma2 goes final?)

[chrisui]

I’m encountering this with a createdBy and updatedBy pattern and it’s leading me down a very verbose road I’m not sure I really want to follow.

Consider following psuedo schema which is quite common…

model ModelA {
  createdBy   User? 
  updatedBy   User? 
}

model ModelB {
  createdBy   User? 
  updatedBy   User? 
}

model ModelC {
  createdBy   User? 
  updatedBy   User? 
}

model User {
  ...
}

I feel I should not have to be explicit about every relation to user in the user model. It should be allowed to simply be referenced in these cases.

Currently to resolve the errors we have to do something like the following

model ModelA {
  createdBy   User?   @relation(name: "UserCreatedModelA")
  updatedBy   User?   @relation(name: "UserUpdatedModelA")
}

model ModelB {
  createdBy   User?   @relation(name: "UserCreatedModelB")
  updatedBy   User?   @relation(name: "UserUpdatedModelB")
}

model ModelC {
  createdBy   User?   @relation(name: "UserCreatedModelC")
  updatedBy   User?   @relation(name: "UserUpdatedModelC")
}

model User {
  createdA   ModelA[]   @relation(name: "UserCreatedModelA")
  updatedA   ModelA[]   @relation(name: "UserUpdatedModelA")
  createdB   ModelB[]   @relation(name: "UserCreatedModelA")
  updatedB   ModelB[]   @relation(name: "UserUpdatedModelA")
  createdC   ModelC[]   @relation(name: "UserCreatedModelA")
  updatedC   ModelC[]   @relation(name: "UserUpdatedModelA")
}

Ambiguous relation detected and then Named relations require an opposite field errors get me here.

[DregondRahl]

I’m facing a similar issue, where almost every table has a createdby/updatedby column. Updating the users table with alias’s is becoming a bit of a challenge. Has there been any update on this possibility ?