GraphQL

# GraphQL 스키마 정의 (SDL)
type User {
  id: ID!
  name: String!
  email: String!
  posts: [Post!]!
  createdAt: DateTime!
}

type Post {
  id: ID!
  title: String!
  content: String!
  author: User!
  published: Boolean!
}

type Query {
  user(id: ID!): User
  users(limit: Int, offset: Int): [User!]!
  post(id: ID!): Post
}

type Mutation {
  createUser(name: String!, email: String!): User!
  createPost(title: String!, content: String!, authorId: ID!): Post!
  publishPost(id: ID!): Post!
}

# 클라이언트 쿼리 예시 - 필요한 필드만 요청
query GetUserWithPosts($userId: ID!) {
  user(id: $userId) {
    id
    name
    posts {
      id
      title
      published
    }
  }
}

# Mutation 예시
mutation CreateNewPost($input: CreatePostInput!) {
  createPost(input: $input) {
    id
    title
    author {
      name
    }
  }
}

// JavaScript 클라이언트 (Apollo Client)
import { gql, useQuery, useMutation } from '@apollo/client';

const GET_USER = gql`
  query GetUser($id: ID!) {
    user(id: $id) {
      id
      name
      email
      posts {
        id
        title
      }
    }
  }
`;

function UserProfile({ userId }) {
  const { loading, error, data } = useQuery(GET_USER, {
    variables: { id: userId },
  });

  if (loading) return <p>로딩 중...</p>;
  if (error) return <p>에러: {error.message}</p>;

  return (
    <div>
      <h1>{data.user.name}</h1>
      <ul>
        {data.user.posts.map(post => (
          <li key={post.id}>{post.title}</li>
        ))}
      </ul>
    </div>
  );
}