How to use Prisma model type in tRPC mutation w/ Zod

I have some models defined in my schema.prisma file. Let's say they look like this:

model Art {
  id        String @id @default(cuid())
  // Some other fields
  creators Creator[]
}

model Creator {
  id        String @id @default(cuid())
  creatorId String
  artId    String
  art      Art   @relation(fields: [artId], references: [id])
}

model Art {
  id        String @id @default(cuid())
  // Some other fields
  creators Creator[]
}

model Creator {
  id        String @id @default(cuid())
  creatorId String
  artId    String
  art      Art   @relation(fields: [artId], references: [id])
}

I am using a tRPC mutation to create an "Art" in my Planetscale database. So, since I'm using Zod, I am doing something like this:

create: privateProcedure
    .input(
      z.object({
        // Some other fields
        creators: (this is where I'm confused)
      })
    )
    .mutation(async ({ input }) => {
      const artistId = ctx.userId;

      const art = await ctx.prisma.art.create({
        data: {
          // Some other fields
          creators: input.creators,
        },
      });

      return art;
    }),

create: privateProcedure
    .input(
      z.object({
        // Some other fields
        creators: (this is where I'm confused)
      })
    )
    .mutation(async ({ input }) => {
      const artistId = ctx.userId;

      const art = await ctx.prisma.art.create({
        data: {
          // Some other fields
          creators: input.creators,
        },
      });

      return art;
    }),

I know I can get the Creator type from Prisma, but I don't know how to tell Zod to expect those properties as the input so that the tRPC procedure will run. I hope I'm explaining this ok because it's kinda hard to put into words lol

4 Replies

peterkyle01•17mo ago

You can nest objects in zod like: .input( z.object({ art: z.object({ id:z.string(), }), creators: z.object({ id: z.string(), //...like that }) }) )

zendev•17mo ago

Ok just gave this a try but TS still throwing a Type error. Here's what it's saying: Type '{ collaboratorId: string; songId: string; }[]' is not assignable to type 'CreatorUncheckedCreateNestedManyWithoutArtInput | CreatorCreateNestedManyWithoutArtInput | undefined'.ts(2322) This is making me think that there should be a way to get the type called "CreatorCreateNestedManyWithoutArtInput" and use it. Also the type itself makes it sound like it's being created without Art input, even though it is? Idk honestly very confused by it all.

ray1sx•17mo ago

You need to define the creators object on the input and then use it when calling the mutation property as you are doing. Try for example:

creators: z.object({
  creatorId: z.string(),
  artId: z.string(),
})

creators: z.object({
  creatorId: z.string(),
  artId: z.string(),
})

If I'm not wrong that is what your Prisma Schema is expecting It is the same @peterkyle01 is saying

zendev•17mo ago

Ok I think I might've figured out what was going wrong - in the mutation I wasn't using the create property. So now in the input it reads:

creators: z.object({
  creatorId: z.string(),
  artId: z.string(),
})

creators: z.object({
  creatorId: z.string(),
  artId: z.string(),
})

And in the mutation it reads:

creators: {
  create: [
    input.creators
  ]
},

creators: {
  create: [
    input.creators
  ]
},

But I'm not including the relation field from the Prisma model in any way - is that necessary? Will it fill in automatically? About to test btw so will update shortly.

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How to use Prisma model type in tRPC mutation w/ Zod