使用Prisma獲得唯一的嵌套值

我有一個看起來像這樣的關系：

model Fighter {
  id          Int     @id @default(autoincrement())
  name        String
  image       String?
  description String?

  battles Battle[]
  votes   Vote[]
}

model Vote {
  Fighter   Fighter @relation(fields: [fighterId], references: [id])
  fighterId Int
  Battle    Battle  @relation(fields: [battleId], references: [id])
  battleId  Int
  count     Int     @default(0)

  @@id([fighterId, battleId])
}

model Battle {
  id       Int       @id @default(autoincrement())
  slug     String    @unique
  name     String
  fighters Fighter[]
  votes    Vote[]
}

一場戰斗有多個戰士，并且有一個投票模型可以計算戰斗中每個戰士的投票。我想檢索一場戰斗，包括戰士并包括每個戰士的投票。我做了這個查詢：

prisma.battle.findMany({
  take: count,
  skip: skip,
  include: {
    fighters: {
      include: {
        votes: {
          select: {
            count: true
          }
        }
      }
    }
  }
});

這大致解決了我的問題，因為結果戰斗機有一系列選票，如下所示：

{
    "id": 2,
    "slug": "Random-1",
    "name": "Random 1",
    "fighters": [
        {
            "id": 3,
            "name": "1 dragon",
            "image": null,
            "votes": [
                {
                    "count": 3
                }
            ]
        },
        {
            "id": 6,
            "name": "1 hero",
            "image": null,
            "votes": [
                {
                    "count": 1
                }
            ]
        }
    ]
}

但我想要的是，最好但我懷疑這是可能的：

{
  "id": 6,
  "name": "1 hero",
  "image": null,
  "votes":  1
}

直接在我的戰斗機物件中計算選票，或者至少在戰斗機物件中只有一票

{
  "id": 6,
  "name": "1 hero",
  "image": null,
  "votes": {
     "count": 1
  }
}

我不知道我的問題是我的模型之間的架構問題，還是我可以使用 Prisma 查詢解決它。我嘗試使用 Prisma 的includeand selectAPI，但我無法解決這個問題。有人對此有任何想法嗎？

uj5u.com熱心網友回復：

您可以使用 _count 子句，它可以讓您獲得類似于您所期望的回應。

這是查詢：

import { PrismaClient } from '@prisma/client';

const prisma = new PrismaClient();

async function main() {
  await prisma.battle.create({
    data: {
      name: 'Battle of the Vowels',
      slug: 'battle-of-the-vowels',
      fighters: {
        create: {
          name: 'Kabal',
          description:
            'Kabal is a fictional character in the Star Wars franchise. He is a member of the Jedi Order.',
          image:
            'https://vignette.wikia.nocookie.net/starwars/images/7/7e/Kabal_HS-SWE.png/revision/latest?cb=20170504075154',
          votes: {
            create: {
              battleId: 1,
            },
          },
        },
      },
    },
  });

  //
  // Updated Query
  //
  const battle = await prisma.battle.findMany({
    // take: count,
    // skip: skip,
    include: {
      fighters: {
        include: {
          _count: {
            select: {
              votes: true,
            },
          },
        },
      },
    },
  });

  console.log(JSON.stringify(battle, null, 2));
}

main()
  .catch((e) => {
    throw e;
  })
  .finally(async () => {
    await prisma.$disconnect();
  });

這是示例回應：

[
  {
    "id": 1,
    "slug": "battle-of-the-vowels",
    "name": "Battle of the Vowels",
    "fighters": [
      {
        "id": 1,
        "name": "Kabal",
        "image": "https://vignette.wikia.nocookie.net/starwars/images/7/7e/Kabal_HS-SWE.png/revision/latest?cb=20170504075154",
        "description": "Kabal is a fictional character in the Star Wars franchise. He is a member of the Jedi Order.",
        "_count": {
          "votes": 1
        }
      }
    ]
  }
]

使用 _count 子句的參考：_count prisma

標籤：javascript 数据库 棱镜

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