createManyAndReturn return order

[alouini333]

Hi,

Today, I was checking the docs regarding createManyAndReturn and I saw the following example.

https://www.prisma.io/docs/orm/prisma-client/queries/relation-queries#using-nested-createmany

const categories = await prisma.category.createManyAndReturn({
  data: [
    { name: 'Fun', },
    { name: 'Technology', },
    { name: 'Sports', }
  ],
  select: {
    id: true
  }
});

const posts = await prisma.post.createManyAndReturn({
  data: [{
    title: "Funniest moments in 2024",
    categoryId: categories[0].id
  }, {
    title: "Linux or macOS — what's better?",
    categoryId: categories[1].id
  },
  {
    title: "Who will win the next soccer championship?",
    categoryId: categories[2].id
  }]
});

This example gives the impression that the returned categories order is matching the input order, even though this is not always the case (Check this discussion here prisma/prisma#24894)

My suggestion is the following, we can update the workaround example like this

const categories = await prisma.category.createManyAndReturn({
  data: [
    { name: 'Fun', },
    { name: 'Technology', },
    { name: 'Sports', }
  ],
  select: {
    id: true
  }
});

const posts = await prisma.post.createManyAndReturn({
  data: [{
    title: "Funniest moments in 2024",
    categoryId: categories.filter(category => category.name === 'Fun')!.id
  }, {
    title: "Linux or macOS — what's better?",
    categoryId: categories.filter(category => category.name === 'Technology')!.id
  },
  {
    title: "Who will win the next soccer championship?",
    categoryId: categories.filter(category => category.name === 'Sports')!.id
  }]
});

Also, I believe that the fact that the order is not garanteed should be mentioned in the remarks of createManyAndReturn section

https://www.prisma.io/docs/orm/reference/prisma-client-reference#createmanyandreturn