Next.js 15 Fullstack Web Apps · 课时

使用 Prisma 处理关系与高级查询

建模一对多和多对多关系，然后使用嵌套写入、include、select、筛选和分页跨关系查询数据。

使用 Prisma 处理关系与高级查询 是 CoddyKit 上的免费 Next.js 15 Fullstack Web Apps 课时。这是第 4 节课，共 4 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 Next.js 15 Fullstack Web Apps 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Next.js 15 Fullstack Web Apps 课程共包含 4 节课。

本课时的部分内容尚未翻译，以英文显示。

Why Relations?

Real data is connected: a user has many posts, a post has many tags. Prisma models these relations in the schema so you can traverse them in type-safe queries.

One-to-Many in the Schema

A one-to-many relation links a parent to many children via a foreign key. Define both sides in the schema.

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

Many-to-Many

Prisma supports implicit many-to-many with just array fields on both sides; it manages the join table for you.

model Post { id Int @id @default(autoincrement()) tags Tag[] }
model Tag  { id Int @id @default(autoincrement()) posts Post[] }

Including Related Data

By default queries return only the model fields. Use include to fetch related records too.

const user = await prisma.user.findUnique({
  where: { id: 1 },
  include: { posts: true },
});

Selecting Specific Fields

Use select to fetch only the columns you need — leaner payloads and faster queries. You can nest select for relations.

const posts = await prisma.post.findMany({
  select: { id: true, title: true, author: { select: { name: true } } },
});

Nested Writes

Create a parent and its children in one call with a nested create. Prisma runs it in a transaction.

await prisma.user.create({
  data: {
    name: 'Ada',
    posts: { create: [{ title: 'Hello' }, { title: 'World' }] },
  },
});

Filtering with where

Build rich filters with operators like contains, gt, in, and combine them with AND/OR.

const recent = await prisma.post.findMany({
  where: {
    published: true,
    title: { contains: 'Prisma' },
  },
});

Filtering on Relations

You can filter a parent by a condition on its children using some, every, or none.

const authors = await prisma.user.findMany({
  where: { posts: { some: { published: true } } },
});

Sorting and Pagination

Order results with orderBy and page with take/skip (offset) for classic pagination.

const page = await prisma.post.findMany({
  orderBy: { createdAt: 'desc' },
  take: 10,
  skip: 20,
});

Cursor Pagination

For large or live datasets, cursor-based pagination is more stable than offset. Pass the last seen id as a cursor.

const next = await prisma.post.findMany({
  take: 10,
  cursor: { id: lastId },
  skip: 1,
});

Avoiding N+1 Queries

Fetching a list and then querying each item separately causes the N+1 problem. Prisma avoids it: use a single include to load relations in one optimized query rather than looping.

Quick Check

Test your Prisma relations knowledge.

Recap

You learned relational querying with Prisma:

Model one-to-many and many-to-many relations in the schema
Fetch relations with include; trim fields with select
Nested writes create parents and children atomically
Filter on relations, paginate with take/skip or cursors, and avoid the N+1 problem

常见问题解答

「使用 Prisma 处理关系与高级查询」课时是免费的吗？

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「使用 Prisma 处理关系与高级查询」这节课中我会学到什么？

建模一对多和多对多关系，然后使用嵌套写入、include、select、筛选和分页跨关系查询数据。你通过在浏览器中直接运行的动手代码来练习 Next.js 15 Fullstack Web Apps，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

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