Enum types in GraphQL - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

What is the output of this GraphQL enum query?

Given this GraphQL enum definition and query, what is the output?

enum Status {
  ACTIVE
  INACTIVE
  PENDING
}

type User {
  id: ID!
  name: String!
  status: Status!
}

query {
  user(id: "1") {
    name
    status
  }
}

Assume the user with id "1" has status ACTIVE.

A {"data": {"user": {"name": "Alice", "status": "ACTIVE"}}}

B {"data": {"user": {"name": "Alice", "status": "active"}}}

C {"data": {"user": {"name": "Alice", "status": 1}}}

D {"error": "Field 'status' is not defined"}

💡 Hint

Enum values in GraphQL are case sensitive and returned as defined.

The enum value is returned exactly as defined in the schema, in uppercase. So the status is "ACTIVE".

🧠 Conceptual

intermediate

Which statement about GraphQL enums is true?

Choose the correct statement about enums in GraphQL.

A Enum values must be unique and are case sensitive, usually uppercase without spaces.

B Enum values can be any string, including lowercase and spaces.

C Enum values can be numbers or booleans.

D Enum values are optional and can be omitted in queries.

💡 Hint

Think about how enums are defined and used in GraphQL schemas.

GraphQL enums must have unique names, are case sensitive, and typically use uppercase letters without spaces.

📝 Syntax

advanced

Identify the syntax error in this enum definition

Which option correctly fixes the syntax error in this GraphQL enum?

enum Color {
  RED
  GREEN
  BLUE
  LIGHT BLUE
}

A Add quotes around 'LIGHT BLUE'

B Replace 'LIGHT BLUE' with 'lightblue'

C Replace 'LIGHT BLUE' with 'LIGHT_BLUE'

D Remove 'LIGHT BLUE' entirely

💡 Hint

Enum values cannot contain spaces.

Enum values must be valid names without spaces. Using underscore is the correct fix.

🔧 Debug

advanced

Why does this GraphQL query fail with an enum argument?

Given this schema snippet:

enum Role {
  ADMIN
  USER
  GUEST
}

type Query {
  usersByRole(role: Role!): [User!]!
}

And this query:

query {
  usersByRole(role: "ADMIN") {
    id
    name
  }
}

Why does the query fail?

A The enum value ADMIN is not defined in the schema

B Enum arguments must be passed without quotes, like role: ADMIN

C The query must use lowercase enum values, like role: admin

D The argument role must be omitted because it is optional

💡 Hint

Think about how enum values are passed as arguments in GraphQL queries.

Enum values are passed without quotes in GraphQL queries. Passing "ADMIN" as a string causes an error.

❓ optimization

expert

Optimize this GraphQL schema using enums

You have a schema with a 'status' field as a string with possible values 'active', 'inactive', 'pending'. Which change optimizes the schema for better validation and clarity?

A Change 'status' to an integer representing each status

B Keep 'status' as a string but add comments listing possible values

C Remove 'status' field and use a boolean 'isActive' instead

D Change 'status' field type to an enum with values ACTIVE, INACTIVE, PENDING

💡 Hint

Enums help restrict values and improve schema clarity.

Using an enum for 'status' restricts allowed values and makes the schema clearer and safer.