GraphQL Input Types

1. Introduction

GraphQL input types are essential for defining the structure of data that can be sent to the server during mutations. They provide a way to enforce data types and validation rules, thus ensuring that the API receives valid and structured data.

2. Definition

An input type in GraphQL is a special type that allows you to define complex input structures. Input types can include scalar types, enums, and other input types, and they are defined using the input keyword.

input CreateUserInput {
    username: String!
    email: String!
    age: Int
}
        

3. Usage of Input Types

Input types are typically used in mutation operations. When defining a mutation, you specify the input type to ensure that the request body matches the expected structure.

type Mutation {
    createUser(input: CreateUserInput!): User!
}
        

4. Best Practices

• Use descriptive names for input types to clarify their purpose.
• Always mark required fields with ! to enforce validation.
• Use nested input types for complex structures to keep code clean and maintainable.
• Document your input types clearly, specifying what each field represents.

5. FAQ