Validation errors in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a validation error in GraphQL?

A validation error happens when a GraphQL query or mutation does not follow the rules of the schema. It means the request is not correct and cannot be processed.

beginner

Name one common cause of validation errors in GraphQL.

One common cause is requesting a field that does not exist in the schema. This means the query asks for data the server does not know about.

intermediate

How does GraphQL help prevent invalid queries?

GraphQL checks queries against the schema before running them. If the query breaks any rules, it returns validation errors instead of running wrong requests.

beginner

What does a validation error response usually include?

It usually includes a message explaining what is wrong, like a missing field or wrong argument type, so the user can fix the query.

beginner

Why is it important to fix validation errors before sending queries to the server?

Fixing validation errors saves time and resources because the server only processes correct queries. It also improves user experience by giving clear feedback.

What causes a validation error in GraphQL?

A Network connection is slow

B Server is down

C Query does not match the schema rules

D Client browser is outdated

Validation errors happen when the query breaks schema rules, not because of server or network issues.

Which of these is NOT a reason for a validation error?

A Querying with correct schema fields

B Requesting a non-existent field

C Using wrong argument types

D Missing required arguments

Using correct schema fields does not cause validation errors.

What does GraphQL do when it finds a validation error?

A Returns an error message

B Runs the query anyway

C Ignores the error

D Restarts the server

GraphQL returns an error message explaining the validation problem.

Validation errors help developers by:

A Hiding mistakes in queries

B Providing clear feedback to fix queries

C Slowing down the server

D Changing the schema automatically

Validation errors give clear feedback so developers can fix their queries.

Which part of GraphQL defines the rules that queries must follow?

A Client

B Resolver

C Network

D Schema

The schema defines the structure and rules for queries in GraphQL.

Explain what a validation error is in GraphQL and why it occurs.

Think about how queries must match the schema.

Describe how GraphQL handles validation errors and why this is helpful for developers.

Consider what happens before the server runs a query.