Fragments for reusable selections in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a fragment in GraphQL?

A fragment is a reusable piece of a query that lets you define a set of fields once and include them in multiple queries or mutations to avoid repetition.

beginner

How do you define a fragment in GraphQL?

You define a fragment using the fragment keyword, followed by a name, the type it applies to, and the fields inside curly braces. Example:

fragment userFields on User { id name email }

beginner

How do you use a fragment inside a GraphQL query?

You include a fragment in a query by using three dots followed by the fragment name. Example:

{ user(id: 1) { ...userFields } }

intermediate

Why are fragments useful in GraphQL?

Fragments help keep queries clean and consistent by reusing field selections. They reduce errors and make it easier to update fields in many places at once.

intermediate

Can fragments be used with different types in GraphQL?

Fragments are defined for a specific type. To reuse fields across different types, you can use interfaces or unions with fragments on those types, but a fragment itself applies to one type only.

What keyword is used to define a fragment in GraphQL?

A fragment

B select

C include

D use

The fragment keyword defines reusable field selections in GraphQL.

How do you include a fragment named userFields inside a query?

A ...userFields

B ... on userFields

C ...userFields()

D ...fragment userFields

You include a fragment by writing three dots followed by the fragment name, like ...userFields.

Fragments in GraphQL help to:

A Create new types

B Reuse field selections to avoid repetition

C Define mutations

D Change the schema

Fragments let you reuse sets of fields in queries to keep them clean and consistent.

Can a fragment be used on multiple different types directly?

A Yes, but only in mutations

B Yes, fragments are universal

C Only if types share the same name

D No, a fragment applies to one specific type

Fragments are defined for one type; to share fields across types, interfaces or unions are used.

Which of the following is a correct fragment definition?

A fragment userFields { id name }

B fragment on User { id name }

C fragment userFields on User { id name }

D fragment userFields User { id name }

The correct syntax includes the fragment name, the type with 'on', and the fields inside braces.

Explain what GraphQL fragments are and how they help when writing queries.

Think about how you might copy-paste fields in many queries and how fragments solve that.

Describe the syntax to define and use a fragment in a GraphQL query.

Remember the three dots when including a fragment.