Nested writes in Prisma orm

Question

My schema looks like this:

model Transaction {
 id                 BigInt       @id @default(autoincrement())
 description        String?      @db.VarChar(256)
 category           Category?    @relation(fields: [categoryId], references: [id])
 createdById        Int          @map("fk_created_by")
 createdBy          UserAccount  @relation("category_fk_created_byTouser_account", fields: [createdById], references: [id]
}

model Category {
  id                      Int                     @id @default(autoincrement())
  name                    String                  @db.VarChar(40)
  categoryFilters         CategoryFilter[]
}

model CategoryFilter {
  id                  BigInt         @id @default(autoincrement())
  words               String         @db.VarChar(255)
  categoryId          Int?           @map("fk_category_id")
}

My question is why this works:

  await prisma.workspaceTransaction.create({
    data: {
      description: 'any',
      createdBy: {
        connect: {
          id: 1
        }
      },
      category: {
        create: {
          name: 'Este é um teste',
          createdById: 1,
          categoryFilters: {
            createMany: {
              data: [
                {
                  words: 'Novo teste'
                }
              ]
            }
          }
        }
      }
    }
  })

And this not?

await prisma.workspaceTransaction.create({
    data: {
      description: 'any',
      createdById: 1,
      category: {
        create: {
          name: 'Este é um teste',
          createdById: 1,
          categoryFilters: {
            createMany: {
              data: [
                {
                  words: 'Novo teste'
                }
              ]
            }
          }
        }
      }
    }
  })

The only difference between those two examples is in createdBy command. And i can create Transaction without nested objects with createdById argument. Any one know why this works this way? Or there is something i am missing?

The error given is: Unknown arg createdById in data.createdById for type TransactionCreateInput

Answer 1

In the second example, you are directly writing a foreign key (createdById) which is considered unsafe, what if there is no UserAccount corresponding to createdById.

While using connect in the first example it would throw an error if Prisma cannot find an UserAccount corresponding to id 1.

First example is the preferred approach.