postgresql - Prisma2 prisma introspect 为外键返回奇怪的值

Question

我有两个表，User 和 Relationship。这些表用于存储父子关系。我正在使用 Postgres

//架构.sql

CREATE TABLE "public"."Relationships" (
    id SERIAL PRIMARY KEY NOT NULL,
    parent_id INT NOT NULL,
    FOREIGN KEY (parent_id) REFERENCES "User" (id),
    child_id INT NOT NULL,
    FOREIGN KEY (child_id) REFERENCES "User" (id)
)

CREATE TABLE "public"."User" (
    id SERIAL PRIMARY KEY NOT NULL,
    name VARCHAR(128) NOT NULL,
    email VARCHAR(128) UNIQUE,
    password VARCHAR(128) NOT NULL,
    isChild BOOLEAN NOT NULL DEFAULT false
    created_at TIMESTAMP NOT NULL DEFAULT NOW();
);  

当我运行 npx prisma introspect 时，schema.prisma 文件中返回以下内容。

//架构.prisma

generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

model Relationships {
  child_id                           Int
  id                                 Int  @default(autoincrement()) @id
  parent_id                          Int
  User_Relationships_child_idToUser  User @relation("Relationships_child_idToUser", fields: [child_id], references: [id])
  User_Relationships_parent_idToUser User @relation("Relationships_parent_idToUser", fields: [parent_id], references: [id])
}

model User {
  created_at                                  DateTime        @default(now())
  email                                       String?         @unique
  id                                          Int             @default(autoincrement()) @id
  ischild                                     Boolean         @default(false)
  name                                        String?
  password                                    String
  Relationships_Relationships_child_idToUser  Relationships[] @relation("Relationships_child_idToUser")
  Relationships_Relationships_parent_idToUser Relationships[] @relation("Relationships_parent_idToUser")
}

我不明白什么是 User_Relationships_child_idToUser 和 User_Relationships_parent_idToUser 以及为什么它们不仅仅是 Prisma 文档教程中针对外键出现的简单语法。

Answer 1

Prisma 的内省(introspection)为每个外键生成两个字段:

• 关系标量字段(基本上是外键的直接表示)
• 一个关系字段(用@relation 属性注释)——这些字段似乎让您感到困惑。它们提供的原因是您可以在 Prisma 客户端 API 中轻松处理这些关系。

您可以在文档中找到更多相关信息 here .

当然 User_Relationships_parent_idToUser 和 User_Relationships_child_idToUser 不是很好听的名字。您可以在内省(introspection)和 rename the relation fields 后手动调整模式有更友好的名字，例如:

model Relationships {
  child_id  Int
  id        Int  @default(autoincrement()) @id
  parent_id Int
  child     User @relation("Relationships_child_idToUser", fields: [child_id], references: [id])
  parent    User @relation("Relationships_parent_idToUser", fields: [parent_id], references: [id])
}