Prisma insert relation one to many

Question

I read about prisma as an ORM provider and than decided to give it a try. My knowledge in database querying especially postrgres is not very experience at the moment, so I got into a situation where I need some help for a proper solution.

Let's assume the following schema.prisma :

model languages {
  language_id                    Int                              @id @default(autoincrement())
  language_code                  String                           @db.VarChar
  translations_categories        translations_categories[]
}

model categories {
  category_id             Int                       @id @default(autoincrement())
  category_name           String                    @db.VarChar
  translations_categories translations_categories[]
}

model translations_categories {
  translation_id    Int        @id @default(autoincrement())
  language_id       Int
  category_id       Int
  translation_value String     @db.VarChar
  categories        categories @relation(fields: [category_id], references: [category_id])
  language          languages  @relation(fields: [language_id], references: [language_id])
}

So I try to solve the following update query with some api data:

1. Add a new category and insert it's category_name
2. Add the given translations for this category within translations_categories (within this step, the provided information contains the language_code , not the language_id !)

The request body contains the following fields:

{
  id: 2
  identifier: "TEST-1"
  translations: {
    de: "german", 
    en: "english", 
    fr: "france", 
    it: "italian"
  }
}

The following questions have arisen:

1. Is it possible to achieve this workflow by a single query?
2. When inserting the translation , I thought it would be possible by the provided language_code on it's own, isn't it?

Answer 1

I would suggest creating the schema in the following manner:

model languages {
  language_id             Int                       @id @default(autoincrement())
  language_code           String                    @unique
  translations_categories translations_categories[]
}

model categories {
  category_id             Int                       @id @default(autoincrement())
  category_name           String
  translations_categories translations_categories[]
}

model translations_categories {
  translation_id    Int        @id @default(autoincrement())
  language_id       Int
  category_id       Int
  translation_value String
  categories        categories @relation(fields: [category_id], references: [category_id])
  language          languages  @relation(fields: [language_id], references: [language_id])

  @@unique([language_id, category_id])
}

The reason for this is that language_code will always be unique for each language so having the @unique would make it much easier to create or update the category.

So you could create/update the category as follows:

let data = {
  id: 2,
  identifier: 'TEST-1',
  translations: {
    de: 'german',
    en: 'english',
    fr: 'france',
    it: 'italian',
  },
}

let translations = Object.entries(data.translations).map(([key, val]) => ({
  language: {
    connectOrCreate: {
      where: { language_code: key },
      create: { language_code: key },
    },
  },
  translation_value: val,
}))

await prisma.categories.upsert({
  where: { category_id: data.id },
  create: {
    category_name: data.identifier,
    translations_categories: { create: translations },
  },
  update: {
    category_name: data.identifier,
    translations_categories: { create: translations },
  },
})