[英]Prisma 3 relation aggregation (sum)
我在嘗試獲取相關數據的總和時遇到了一些麻煩。
這是我的架構:
model Vote {
userId Int
user User @relation(fields: [userId], references: [id])
itemId Int
item Item @relation(fields: [itemId], references: [id])
value Int
@@id([userId, itemId])
}
model Item {
id Int @id @default(autoincrement())
userId Int
user User @relation(fields: [userId], references: [id])
listId Int
list List @relation(fields: [listId], references: [id])
votes Vote[]
body String @db.VarChar(255)
createdAt DateTime @default(now())
updatedAt DateTime @updatedAt
}
model List {
id Int @id @default(autoincrement())
userId Int
user User @relation(name: "Ownership", fields: [userId], references: [id])
items Item[]
sharedWith User[] @relation(name: "Shared")
title String @db.VarChar(255)
description String?
createdAt DateTime @default(now())
updatedAt DateTime @updatedAt
}
model User {
id Int @id @default(autoincrement())
email String @unique
password String
name String?
lists List[] @relation(name: "Ownership")
items Item[]
votes Vote[]
sharedWith List[] @relation(name: "Shared")
createdAt DateTime @default(now())
updatedAt DateTime @updatedAt
}
我想要得到的是:
這就是我想出的:
prisma.list.findUnique({
where: { id },
include: {
items: {
include: {
votes: {
include: {
_sum: {
select: {
value: true,
},
},
},
},
},
},
},
})
我根據在網上找到的多個不同的查詢(其中大部分在 Prisam Docs 中)構建了查詢。
我還注意到 Prisma Docs 缺少很多東西,例如(添加/刪除相關數據 - 多對多關系)。 有沒有更好的文檔,或者像這樣的東西的示例項目?
謝謝!
這目前不可能作為單個查詢。 您可以做的是在取回這些值后對它們求和。
我基於 StackOverflow 創建了一個類似的示例。 鑒於以下 Prisma 架構:
// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema
datasource db {
provider = "postgresql"
url = env("DATABASE_URL")
}
generator client {
provider = "prisma-client-js"
}
model User {
id Int @id @default(autoincrement())
name String
votes Vote[]
questions Question[]
}
model Question {
id Int @id @default(autoincrement())
question String
votes Vote[]
user User @relation(fields: [userId], references: [id])
userId Int
}
model Vote {
id Int @id @default(autoincrement())
value Int @default(1)
questionId Int
question Question @relation(fields: [questionId], references: [id])
user User @relation(fields: [userId], references: [id])
userId Int
}
您可以編寫以下腳本:
import { PrismaClient } from "@prisma/client"
const prisma = new PrismaClient()
async function main() {
const users = await prisma.user.findMany({
include: {
questions: {
include: {
votes: {
select: {
value: true,
},
},
},
},
},
})
for (let user of users) {
for (let question of user.questions) {
let vote_sum = 0
for (let vote of question.votes) {
vote_sum += vote.value
}
;(question as any).vote_sum = vote_sum
}
}
console.dir(users, { depth: Infinity })
}
main().catch((err) => console.error(err))
然后在取回數據后對這些值求和。
如果這對您不起作用,我鼓勵您為 Prisma 團隊編寫功能請求。
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