Improve relation syntax for simple scenarios

Problem

Right now, defining a relation in the Prisma schema is quite verbose due to the required relation scalar field:

model User {
  id        Int      @id @default(autoincrement())
  posts     Post[]
}

model Post {
  id        Int   @id @default(autoincrement())
   author    User  @relation(fields: [authorId], references: [id])
   authorId  Int  // relation scalar field 
} 

In implicit m-n-relations, we also need to use the @relation attribute: (You don't need them now)

model Post {
  id         Int        @id @default(autoincrement())
  categories Category[] @relation(references: [id])
}

model Category {
  id    Int    @id @default(autoincrement())
  posts Post[] @relation(references: [id])
}

Solution

Maybe we can figure out a way how Prisma can infer the information that's currently made explicit in the schema. Another solution could be to add a feature to the Prisma schema formatter which can insert the required fields automatically.

Start by reviewing the Prisma schema relation examples and the discussion around relation scalar fields. The issue presents two possible directions—inference or formatter support—without selecting one. Done would require an agreed approach that makes simple relations less verbose while preserving correct relation information.