Schema definition in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a schema in GraphQL?

A schema in GraphQL defines the types of data you can query or mutate. It acts like a blueprint for what data is available and how clients can ask for it.

beginner

What does the type Query represent in a GraphQL schema?

The type Query defines the entry points for reading or fetching data. It lists all the queries clients can make to get data from the server.

intermediate

Explain the role of type Mutation in a GraphQL schema.

type Mutation defines the operations that change data, like creating, updating, or deleting. It tells clients how they can modify data on the server.

beginner

What is the purpose of scalar types in GraphQL schema?

Scalar types represent the basic data types like Int, String, Boolean, Float, and ID. They are the building blocks for defining fields.

beginner

How do you define a custom object type in a GraphQL schema?

You define a custom object type using the type keyword followed by the name and its fields with their types. For example:<br>type Book { id: ID! title: String! author: String }

What keyword starts the definition of a GraphQL schema's query type?

A type Query

B schema Query

C query Type

D define Query

The query type is defined using the keyword type Query in GraphQL schema.

Which GraphQL type is used to represent a unique identifier?

A String

B ID

C Int

D Boolean

The ID scalar type is used to represent unique identifiers in GraphQL.

What does the exclamation mark (!) mean in a GraphQL type definition like String!?

A List of strings

B Nullable field

C Optional field

D Non-nullable field

The exclamation mark means the field is non-nullable, so it must always have a value.

Which part of the schema defines how to change data?

A type Mutation

B type Query

C type Subscription

D type Change

type Mutation defines operations that modify data in GraphQL.

How do you define a list of strings in GraphQL schema?

A String[]

B List<String>

C [String]

D Array<String>

Lists are defined using square brackets, like [String] in GraphQL.

Describe the main components of a GraphQL schema and their roles.

Think about how clients ask for data and how they change data.

Explain how you would define a new object type with fields in a GraphQL schema.

Imagine describing a real-world object like a book or user.