GraphQL

A query language APIs can support to enable SQL-like behavior across APIs; supports both query and mutation, and can define complex entity descriptions.

Website

Cheat sheet

Implementations

Reading

Many additional implementations from Apollo project.

Schema
schema GraphQL schema definition
query Read and traverse data
mutation Modify data or trigger an action
subscription Run a query when an event occurs

Built-in Scalar Types
Int Signed 32‐bit integer
Float Signed double-precision floating-point value
String UTF‐8 character sequence
Boolean true or false
ID A Unique identifier

Type Definitions
scalar Scalar Type
type Object Type
interface Interface Type
union Union Type
enum Enum Type
input Input Object Type

Type Modifiers
String Nullable String
String! Non-null String
[String] List of nullable Strings
[String]! Non-null list of nullable Strings
[String!]! Non-null list of non-null Strings

Input Arguments {.row-span-2}

Basic Input

type Query {
    users(limit: Int): [User]
}

Input with default value

type Query {
    users(limit: Int = 10): [User]
}

Input with multiple arguments

type Query {
    users(limit: Int, sort: String): [User]
}

Input with multiple arguments and default values

type Query {
    users(limit: Int = 10, sort: String): [User]
}
type Query {
    users(limit: Int, sort: String = "asc"): [User]
}
type Query {
    users(limit: Int = 10, sort: String = "asc"): [User]
}

Input Types

input ListUsersInput {
    limit: Int
    since_id: ID
}

type Mutation {
    users(params: ListUsersInput): [User]!
}

Custom Scalars

scalar Url
type User {
    name: String
    homepage: Url
}

Interfaces

interface Foo {
    is_foo: Boolean
}
interface Goo {
    is_goo: Boolean
}
type Bar implements Foo {
    is_foo: Boolean
    is_bar: Boolean
}
type Baz implements Foo, Goo {
    is_foo: Boolean
    is_goo: Boolean
    is_baz: Boolean
}

Object implementing one or more Interfaces

Unions

type Foo {
    name: String
}
type Bar {
    is_bar: String
}
union SingleUnion = Foo
union MultipleUnion = Foo | Bar
type Root {
    single: SingleUnion
    multiple: MultipleUnion
}

Union of one or more Objects

Enums

enum USER_STATE {
    NOT_FOUND
    ACTIVE
    INACTIVE
    SUSPENDED
}
type Root {
    stateForUser(userID: ID!): USER_STATE!
    users(state: USER_STATE, limit: Int = 10): [User]
}

Also see

Tags: format   distribution   presentation   storage  

Last modified 06 April 2022