# Using nullability in GraphQL

DevFeed: [Using nullability in GraphQL](<https://devfeed.tech/articles/using-nullability-in-graphql-23564.md>)

Original publisher: [Read original article](<https://www.apollographql.com/blog/using-nullability-in-graphql>)

Author: Sashko Stubailo

Published: 2018-06-05T18:17:00Z

Content type: tutorial

Language: en

Sources: [Apollo Blog](<https://devfeed.tech/sources/apollo-blog.md>)

Topics: [GraphQL](<https://devfeed.tech/topics/graphql.md>), [REST API](<https://devfeed.tech/topics/rest-api.md>), [JavaScript](<https://devfeed.tech/topics/javascript.md>)

Tags: [code](<https://devfeed.tech/tags/code.md>), [frontend](<https://devfeed.tech/tags/frontend.md>), [graphql](<https://devfeed.tech/tags/graphql.md>), [javascript](<https://devfeed.tech/tags/javascript.md>), [rest-api](<https://devfeed.tech/tags/rest-api.md>), [schema](<https://devfeed.tech/tags/schema.md>)

## AI overview

This tutorial explains GraphQL nullability, including the difference between nullable and non-null fields, how non-null markers affect query results, and when to use them in a schema.

## Source excerpt

When you're working with a REST API, you don't always know exactly what fields you're going to get back when you call an endpoint. GraphQL improves on that by having a complete schema of your available data, and giving you back exactly the fields you asked for. But what if a field is simply not available, for example if the record you're retrieving never got that value assigned, or there was an error fetching a piece of data?