[prisma]prisma外部キー構文

One-to-many relations(user(one) - Book(many))

model User {
  id    Int    @id @default(autoincrement())
  books Book[]
}

model Book {
  id       Int  @id @default(autoincrement())
  author   User @relation(fields: [authorId], references: [id])
  authorId Int
}

CREATE TABLE "User" (
    id SERIAL PRIMARY KEY
);
CREATE TABLE "Book" (
    id SERIAL PRIMARY KEY,
    "authorId" integer NOT NULL,
    FOREIGN KEY ("authorId") REFERENCES "User"(id)
);

one to one relation

model User {
  id      Int      @id @default(autoincrement())
  profile Profile?
}

model Profile {
  id     Int  @id @default(autoincrement())
  user   User @relation(fields: [userId], references: [id])
  userId Int 
}

CREATE TABLE "User" (
    id SERIAL PRIMARY KEY
);
CREATE TABLE "Profile" (
    id SERIAL PRIMARY KEY,
    "userId" INTEGER NOT NULL UNIQUE,
    FOREIGN KEY ("userId") REFERENCES "User"(id)
);

many to many

model Post {
  id         Int                 @id @default(autoincrement())
  title      String
  categories CategoriesOnPosts[]
}

model Category {
  id    Int                 @id @default(autoincrement())
  name  String
  posts CategoriesOnPosts[]
}

model CategoriesOnPosts {
  post       Post     @relation(fields: [postId], references: [id])
  postId     Int // relation scalar field (used in the `@relation` attribute above)
  category   Category @relation(fields: [categoryId], references: [id])
  categoryId Int // relation scalar field (used in the `@relation` attribute above)
  assignedAt DateTime @default(now())
  assignedBy String

  @@id([postId, categoryId])
}

CREATE TABLE "Category" (
    id SERIAL PRIMARY KEY
);
CREATE TABLE "Post" (
    id SERIAL PRIMARY KEY
);
-- Relation table + indexes -------------------------------------------------------
CREATE TABLE "CategoriesOnPosts" (
    "categoryId" integer NOT NULL,
    "postId" integer NOT NULL,
    "assignedBy" text NOT NULL
    "assignedAt" timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY ("categoryId")  REFERENCES "Category"(id),
    FOREIGN KEY ("postId") REFERENCES "Post"(id)
);
CREATE UNIQUE INDEX "CategoriesOnPosts_category_post_unique" ON "CategoriesOnPosts"("categoryId" int4_ops,"postId" int4_ops);