Hi I m having hard time to adapt the concept of supertype su Prisma #orm-help

Hi, I’m having hard time to adapt the concept of ...

Ofer

04/23/2021, 12:37 PM

Hi, I’m having hard time to adapt the concept of supertype-subtype in Prisma schema. For example how do I implement this in Prisma schema terms? If I would do it like the typical 1-n prisma example:

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model Product {
  id        Int      @id @default(autoincrement())
  cars     Car[]
  boats    Boat[]
  planes.  Plane[]
}

model Car {
  id        Int   @id @default(autoincrement())
  product   Product  @relation(fields: [productId], references: [id])
  productId  Int
}

model Boat {
  id        Int   @id @default(autoincrement())
  product   Product  @relation(fields: [productId], references: [id])
  productId  Int
}

model Plane {
  id        Int   @id @default(autoincrement())
  product   Product  @relation(fields: [productId], references: [id])
  productId  Int
}

But it doesn’t feel intuitive to me. Is this the correct way in this case?

Robert Witchell

04/25/2021, 2:32 AM

can the product be of multiple cars? wouldn't it be 1-1? the Product is a car?

Robert Witchell

04/25/2021, 2:41 AM

I'm not sure if it's the "best" way, but if you kept down this current path, you could:

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model Product {
  id        Int      @id @default(autoincrement())
  carId     Int
  car       Car
  boatId    Int
  boat      Boat
  planeId   Int
  plane     Plane
}

and then in your model you could have:

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const Product = objectType({
  name: 'Product',
  definition(t) {
    t.model.id()
    t.model.car()
    t.model.carId()
    t.model.boat()
    t.model.boatId()
    t.model.plane()
    t.model.planeId()
    t.field.productType({
      resolve: (parent, args, context, info) => {
        if (parent.carId) {
          return PRODUCT_ENUM_CAR
        }
        // etc
      },
    })
    t.field.getProductType({/*more here*/})
  },
})

Ofer

04/25/2021, 5:25 AM

The problem with this approach is that is not going to scale well. The Car,Plane, Boat is just a simplified example. In reality I Could have many subtypes (20-30)

Mark

04/25/2021, 7:06 PM

Not sure if there’s a better way, but just commenting on what you have ^ if it’s 1:1, why is it not like this:

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model Product {
  id        Int      @id @default(autoincrement())
  car     Car?
  boat    Boat?
  plane  Plane?
}
model Car {
  id        Int   @id @default(autoincrement())
  product   Product  @relation(fields: [productId], references: [id])
  productId  Int  @unique
}
model Boat {
  id        Int   @id @default(autoincrement())
  product   Product  @relation(fields: [productId], references: [id])
  productId  Int  @unique
}
model Plane {
  id        Int   @id @default(autoincrement())
  product   Product  @relation(fields: [productId], references: [id])
  productId  Int  @unique
}

Mark

04/25/2021, 7:12 PM

If I was doing this in Nexus, I’d probably also add a

productType

enum field to the

model Product

, and make an object type like this:

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const product = objectType({
  name: 'Product',
  definition(t) {
    t.int('id')
    t.field('productType', { type: 'ProductTypeEnum' })
    t.field('details', {
      type: 'DetailsUnionType',
      resolve(root, _args, { prisma }) {
        if (root.productType === 'CAR') {
          return prisma.product.findUnique({ where: { id: root.id }}).car()
        } else ...
      }
    })
  }
})

🤷

Robert Witchell

04/26/2021, 1:21 AM

even:

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resolve(root, _args, { prisma }) {
 return prisma[productType].findUnique({ where: { id: root.id }}).{productType}()
}

Mark

04/26/2021, 1:37 AM

haha yeah. or

prisma[root.productType].findUnique({ where: { productId: root.id } })

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