如何与现有记录创建新的多对多关系？答案

【问题标题】：How to create a new many to many relationship with existing records?如何与现有记录创建新的多对多关系？
【发布时间】：2022-01-27 00:16:05
【问题描述】：

我有一个多对多关系建模拳击比赛：

一场战斗可以有多个战士（总是 2 个）
一名战士可以参加多次战斗

我的架构如下所示：

model Fight {
  id            Int     @id @default(autoincrement())
  fighters      FighterFights[]
}

model Fighter {
  id        Int     @id @default(autoincrement())
  name      String  @unique
  fights    FighterFights[]
}

model FighterFights {
  fighter      Fighter     @relation(fields: [fighterId], references: [id])
  fighterId    Int
  fight        Fight @relation(fields: [fightId], references: [id])
  fightId      Int

  @@id([fighterId, fightId])
}

我想用 2 名现有战士创建新的战斗。这是我尝试过的：

const result = await prisma.fight.create({
  data: {
    fighters: {
      connect: [{ id: fighter1 }, { id: fighter2 }],
    },
  },
})

但我收到此打字稿错误：

Type '{ id: any; }' is not assignable to type 'FighterFightsWhereUniqueInput'.
  Object literal may only specify known properties, and 'id' does not exist in type 'FighterFightsWhereUniqueInput'.

我的prisma.fight.create 函数调用应该是什么样子？

【问题讨论】：

标签： typescript postgresql many-to-many prisma

【解决方案1】：

你可以这样做：

const { PrismaClient } = require('@prisma/client')
const prisma = new PrismaClient()

const saveData = async () => {
  const fighter1 = await prisma.fighter.create({
    data: {
      name: 'Ryu',
    },
  })
  const fighter2 = await prisma.fighter.create({
    data: {
      name: 'Ken',
    },
  })

  console.log(JSON.stringify(fighter1, null, 2));
  console.log(JSON.stringify(fighter2, null, 2));

  const fight = await prisma.fight.create({
    data: {
      fighters: {
        createMany: {
          data: [
            {
              fighterId: fighter1.id,
            },
            {
              fighterId: fighter2.id,
            },
          ]
        },
      },
    },
    select: {
      id: true,
      fighters: {
        select: {
          fighter: true,
        },
      },
    },
  });

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

saveData()

它将返回以下内容

【讨论】：