graphql-fundamentals

This skill covers the essential GraphQL concepts every developer needs. From type definitions to query operations, you'll learn the foundation for building GraphQL APIs.

| Scalar | String, Int, Float, Boolean, ID | name: String! | | Object | type Name { fields } | type User { id: ID! } | | Input | input Name { fields } | input CreateUserInput { name: String! } | | Enum | enum Name { VALUES } | enum Status { ACTIVE INACTIVE } | | List | [Type] or [Type!]! | tags: [String!]! | | Non-null | Type! | id: ID! |

| Cannot query field "x" | Field not in schema | Check spelling, verify schema | | Variable "$x" not defined | Missing variable declaration | Add to query signature | | Expected non-null, got null | Resolver returned null for ! field | Fix resolver or make nullable | | Unknown type "X" | Type not defined | Add type definition |