SQL database resolvers in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a SQL database resolver in GraphQL?

A SQL database resolver is a function in GraphQL that fetches data from a SQL database when a query or mutation is executed. It connects GraphQL queries to the database.

beginner

How does a resolver function typically interact with a SQL database?

It runs SQL queries or commands to get or modify data, then returns the results to GraphQL to send back to the client.

intermediate

Why do we use resolvers in GraphQL instead of direct SQL queries in the client?

Resolvers keep the database secure and hidden. They let the server control what data is sent and how, avoiding direct database access from clients.

intermediate

What is the role of arguments in SQL database resolvers?

Arguments let clients specify details like which records to fetch or update. The resolver uses these to build the right SQL query.

beginner

Give an example of a simple SQL database resolver for fetching a user by ID.

Example resolver: async function getUser(parent, args) { return await db.query('SELECT * FROM users WHERE id = ?', [args.id]); }

What does a SQL database resolver do in GraphQL?

A Creates the GraphQL schema

B Fetches or modifies data in a SQL database

C Runs client-side JavaScript

D Styles the GraphQL interface

Resolvers connect GraphQL queries to the database by fetching or modifying data.

Why should clients not run SQL queries directly in GraphQL?

A To keep the database secure and control data access

B Because SQL queries are too slow

C Because GraphQL only works with NoSQL databases

D Because SQL is not supported by GraphQL

Resolvers protect the database by controlling access and hiding direct queries from clients.

What do resolver arguments help with?

A They define the database schema

B They style the GraphQL response

C They run SQL commands on the client

D They specify which data to fetch or update

Arguments let clients tell the resolver what specific data they want.

Which of these is a typical step inside a SQL database resolver?

A Rendering HTML

B Compiling CSS

C Running a SQL query

D Sending emails

Resolvers run SQL queries to get or change data in the database.

What is returned by a SQL database resolver?

A Data fetched from the database

B Raw SQL code

C GraphQL schema definitions

D Client-side scripts

Resolvers return the data fetched from the database to GraphQL.

Explain in your own words what a SQL database resolver does in a GraphQL server.

Think about how GraphQL gets data from a SQL database.

Describe why using resolvers improves security compared to letting clients run SQL queries directly.

Consider what could happen if clients had direct database access.