Bidirectional relationships in GraphQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a bidirectional relationship field in GraphQL schema.

GraphQL

type Author {
  id: ID!
  name: String!
  books: [Book][1]
}

type Book {
  id: ID!
  title: String!
  author: Author
}

Drag options to blanks, or click blank then click option'

A@relation(name: "BooksByAuthor")

B@relation(name: "AuthorBooks")

C@relation(name: "AuthorToBooks")

D@relation(name: "BooksAuthor")

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the @relation directive causes the relationship to be unidirectional.

Using inconsistent relation names on both sides.

The @relation(name: "BooksByAuthor") directive defines the bidirectional link between Author.books and Book.author.

2fill in blank

medium

Complete the code to define the inverse side of the bidirectional relationship.

GraphQL

type Book {
  id: ID!
  title: String!
  author: Author[1]
}

Drag options to blanks, or click blank then click option'

A@relation(name: "AuthorBooks")

B@relation(name: "BooksAuthor")

C@relation(name: "AuthorToBooks")

D@relation(name: "BooksByAuthor")

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different relation name breaks the bidirectional link.

Forgetting to add the @relation directive on one side.

The @relation(name: "BooksByAuthor") directive on Book.author matches the name used on Author.books to create a bidirectional link.

3fill in blank

hard

Fix the error in the bidirectional relationship by completing the missing directive.

GraphQL

type Author {
  id: ID!
  name: String!
  books: [Book][1]
}

type Book {
  id: ID!
  title: String!
  author: Author
}

Drag options to blanks, or click blank then click option'

A@relation(name: "BooksByAuthor")

B@relation(name: "AuthorToBooks")

C@relation(name: "BooksAuthor")

D@relation(name: "AuthorBooks")

Attempts:

3 left

💡 Hint

Common Mistakes

Using different relation names on each side.

Missing the @relation directive on one side.

The correct relation name @relation(name: "BooksByAuthor") must be used to match the inverse side and fix the bidirectional link.

4fill in blank

hard

Fill both blanks to define a bidirectional relationship with explicit foreign key field.

GraphQL

type Author {
  id: ID!
  name: String!
  books: [Book][1]
}

type Book {
  id: ID!
  title: String!
  authorId: ID!
  author: Author[2]
}

Drag options to blanks, or click blank then click option'

A@relation(name: "BooksByAuthor")

B@relation(name: "AuthorBooks")

C@relation(name: "BooksByAuthor", fields: [authorId], references: [id])

D@relation(name: "AuthorBooks", fields: [authorId], references: [id])

Attempts:

3 left

💡 Hint

Common Mistakes

Using different relation names.

Omitting fields and references on the foreign key side.

The @relation(name: "BooksByAuthor") on Author.books and @relation(name: "BooksByAuthor", fields: [authorId], references: [id]) on Book.author define a bidirectional relationship with explicit foreign key.

5fill in blank

hard

Fill all three blanks to define a bidirectional relationship with custom relation name and explicit foreign key.

GraphQL

type User {
  id: ID!
  username: String!
  posts: [Post][1]
}

type Post {
  id: ID!
  content: String!
  userId: ID!
  user: User[2][3]
}

Drag options to blanks, or click blank then click option'

A@relation(name: "UserPosts")

B@relation(name: "UserPosts", fields: [userId]

C, references: [id])

D@relation(name: "PostsByUser")

Attempts:

3 left

💡 Hint

Common Mistakes

Using different relation names on each side.

Forgetting to add references on the foreign key side.

The @relation(name: "UserPosts") on User.posts and @relation(name: "UserPosts", fields: [userId]) plus , references: [id] on Post.user define a bidirectional relationship with a custom name and explicit foreign key.