การออกแบบสคีมา GraphQL แรกของคุณ

A GraphQL schema is the blueprint of your API: it defines what data clients can ask for and how it’s structured. It’s the core of every GraphQL service.

You write schemas in the Schema Definition Language (SDL) — a simple, readable syntax for declaring object types, their fields, and how they relate.

The core building block is the object type, declared with the type keyword. Like a class, it represents a kind of object you can fetch.

Fields hold data via built-in scalar types: String, Int, Float, Boolean, and ID for unique identifiers.

Add ! after a type to make a field non-null — it must always have a value. Query it and the server must return one or it errors.

Wrap a type in [] for a list. Stack the ! too: [String!]! means a non-null list of non-null strings.

Every schema needs the root Query type — it defines all the entry points for clients to read data. Queries always start here.

Fields on Query are the data you can fetch, and they take arguments to filter — like book(id: ID!): Book to grab one book by id.

Here it all comes together: Author and Book types, a Query entry point, and a Book.author field that links the two. Relationships!

You designed a real schema: object types with the type keyword, scalar fields, ! for non-null, [] for lists, and Query as the read entry point.