# GraphQL Cheatsheet

# GraphQL Cheatsheet

## Overview of unique features

- Query language for APIs
- Allows clients to specify exactly what data they need
- Supports introspection and self-documentation
- Can be used for building efficient and flexible APIs

## Querying

```graphql
# Query for a specific field
{
user(id: "123") {
name
email
}
}

# Query for a specific field with an alias
{
john: user(id: "123") {
name
}
jane: user(id: "456") {
name
}
}

# Query for a field with arguments
{
users(role: "admin") {
name
}
}

# Query for a field with nested objects
{
user(id: "123") {
name
posts {
title
content
}
}
}
```

## Mutations

```graphql
# Create a new user
mutation {
createUser(input: {name: "John", email: "[email protected]"}) {
id
name
email
}
}

# Update an existing user
mutation {
updateUser(id: "123", input: {name: "John Doe"}) {
id
name
email
}
}

# Delete a user
mutation {
deleteUser(id: "123") {
id
name
email
}
}
```

## Fragments

```graphql
# Define a fragment
fragment UserInfo on User {
name
email
}

# Use a fragment in a query
{
user(id: "123") {
...UserInfo
}
}

# Define a fragment with variables
```graphql
# Define a fragment with variables
fragment UserInfo on User {
name
email
posts(first: $count) {
title
content
}
}

# Use a fragment with variables
query($count: Int!) {
user(id: "123") {
...UserInfo
}
}
```

## Directives

```graphql
# Use a directive to conditionally include a field
{
user(id: "123") {
name
email
posts @include(if: $withPosts) {
title
content
}
}
}
```

## Schema

```graphql
# Define a schema
type User {
id: ID!
name: String!
email: String!
posts: [Post!]!
}

type Post {
id: ID!
title: String!
content: String!
author: User!
}

type Query {
user(id: ID!): User
posts: [Post!]!
}

type Mutation {
createUser(input: CreateUserInput!): User!
updateUser(id: ID!, input: UpdateUserInput!): User!
deleteUser(id: ID!): User!
}

input CreateUserInput {
name: String!
email: String!
}

input UpdateUserInput {
name: String
email: String
}
```

## Resources

- [GraphQL documentation](https://graphql.org/learn/)
- [GraphQL tutorial](https://www.tutorialspoint.com/graphql/index.htm)
- [GraphQL forum](https://stackoverflow.com/questions/tagged/graphql) for community support and troubleshooting.