Prisma2:如何用Paljs解决n +1问题

Question

谢谢你的帮助。

我在前端使用阿波罗客户端，在后端使用graphql-nexus，prisma2和graphql-yoga服务器。

我想用@paljs/plugins解决n+1问题。

在前台，我有一个查询帖子，比如：

query posts{
    posts {
        id
        favoritedBy(where: { id: { equals: $currentUserId } }) {
            id
        }
        author {
            id
            avatar {
                id
            }
        }
        link {
            id
        }
        games {
            id
        }
        tags {
            id
        }
        likes(where: { user: { id: { equals: $currentUserId } } }) {
            id
        }
    }
}

帖子解析器：

import { PrismaSelect } from '@paljs/plugins'
export const posts = queryField('posts', {
  type: 'Post',
  list: true,
  args: {
    ...
  },
  resolve: async (_parent, args, { prisma, request }, info) => {
    const select = new PrismaSelect(info).value
    let opArgs: FindManyPostArgs = {
      take: 10,
      orderBy: {
        [args.orderBy]: 'desc',
      },
      ...select
    }

    const post = await prisma.post.findMany(opArgs)
    
    //The result I want to return with the "sub-models" like likes, author tags...
    console.log(JSON.stringify(post, undefined, 2))

    return post
  },
})

我记录查询

const prisma = new PrismaClient({
  log: ['query'],
})

我的问题:有了PrismaSelect，我有比没有PrismaSelect多5个查询，如果我在前端检查请求时间，我需要用300-400ms的时间。那么我做错了什么呢？我在@paljs/plugins文档中看到了上下文中的select。也许这就是我的错误。如何在上下文中使用select？

下面是我的上下文：

import { PrismaClient, PrismaClientOptions } from '@prisma/client'
import { PubSub } from 'graphql-yoga'
import { PrismaDelete, onDeleteArgs } from '@paljs/plugins'

class Prisma extends PrismaClient {
  constructor(options?: PrismaClientOptions) {
    super(options)
  }

  async onDelete(args: onDeleteArgs) {
    const prismaDelete = new PrismaDelete(this)
    await prismaDelete.onDelete(args)
  }
}

export const prisma = new PrismaClient({
  log: ['query'],
})
export const pubsub = new PubSub()

export interface Context {
  prisma: PrismaClient
  request: any
  pubsub: PubSub
}

export function createContext(request: any): Context {
  return { prisma, request, pubsub }
}

Answer 1

您需要知道，要使用我的PrismaSelect插件，您需要删除nexus-prisma-plugin包，并使用我的Pal.js CLI创建用于nexus的CRUD和ObjectType，并使用@paljs/nexus插件添加mackSchema函数

import { makeSchema } from '@nexus/schema';
import * as types from './graphql';
import { paljs } from '@paljs/nexus'; // import our plugin

export const schema = makeSchema({
  types,
  plugins: [paljs()],// here our plugin don't use nexus-prisma-plugin
  outputs: {
    schema: __dirname + '/generated/schema.graphql',
    typegen: __dirname + '/generated/nexus.ts',
  },
  typegenAutoConfig: {
    sources: [
      {
        source: require.resolve('./context'),
        alias: 'Context',
      },
    ],
    contextType: 'Context.Context',
  },
});

现在将此类型添加到您的Context

export interface Context {
  prisma: PrismaClient
  request: any
  pubsub: PubSub
  select: any // here our select type
}
export function createContext(request: any): Context {
// our paljs plugin will add select object before resolver
  return { prisma, request, pubsub, select: {} }
}

添加我们的插件后，您的查询将如下所示

extendType({
  type: 'Query',
  definition(t) {
    t.field('findOneUser', {
      type: 'User',
      nullable: true,
      args: {
        where: arg({
          type: 'UserWhereUniqueInput',
          nullable: false,
        }),
      },
      resolve(_, { where }, { prisma, select }) {
// our plugin add select object into context for you
        return prisma.user.findOne({
          where,
          ...select,
        });
      },
    });
  },
});

您是否可以尝试使用我的pal c命令从我的列表中启动一个示例，并尝试您的模式并对其进行测试

Answer 2

它正在工作，thx Ahmed你的插件真棒！

我将我的Post-Object从

const Post = objectType({
  name: 'Post',
  definition(t) {
    t.model.id()
    t.model.authorId()
    t.model.tags()
    t.model.games()
    t.model.link()
    t.model.report()
    t.model.notifications()
    t.model.author()
    t.model.favoritedBy({
      filtering: {
        id: true,
      },
    })
    t.model.likes({
      filtering: {
        user: true,
      },
    })
  }
})

至

const Post = objectType({
  name: 'Post',
  definition(t) {
    t.string('id')
    t.field('tags', {
      nullable: false,
      list: [true],
      type: 'Tag',
      resolve(parent: any) {
        return parent['tags']
      },
    })
    t.field('games', {
      list: [true],
      type: 'Game',
      resolve(parent: any) {
        return parent['games']
      },
    })
    t.field('link', {
      type: 'Link',
      nullable: true,
      resolve(parent: any) {
        return parent['link']
      },
    })
    t.field('notifications', {
      list: [true],
      type: 'Notification',
      resolve(parent: any) {
        return parent['notifications']
      },
    })
    t.field('author', {
      nullable: false,
      type: 'User',
      resolve(parent: any) {
        return parent['author']
      },
    })
    t.field('favoritedBy', {
      nullable: false,
      list: [true],
      type: 'User',
      args: {
        where: 'UserWhereInput',
      },
      resolve(parent: any) {
        return parent['favoritedBy']
      },
    })
    t.field('likes', {
      list: [true],
      type: 'Like',
      args: {
        where: 'LikeWhereInput',
      },
      resolve(parent: any) {
        return parent['likes']
      },
    })
  },
})

我还同时使用了plugin和paljs-plugin