GraphQL Implementation

Table of Contents

• [Overview](#overview)
• [When to Use](#when-to-use)
• [Quick Start](#quick-start)
• [Reference Guides](#reference-guides)
• [Best Practices](#best-practices)

Overview

Implement GraphQL APIs with proper schema design, resolver patterns, error handling, and performance optimization for flexible client-server communication.

When to Use

• Designing new GraphQL APIs
• Creating GraphQL schemas and types
• Implementing resolvers and mutations
• Adding subscriptions for real-time data
• Migrating from REST to GraphQL
• Optimizing GraphQL performance

Quick Start

Minimal working example:

type User {
  id: ID!
  email: String!
  firstName: String!
  lastName: String!
  role: UserRole!
  posts: [Post!]!
  createdAt: DateTime!
  updatedAt: DateTime!
}

enum UserRole {
  ADMIN
  USER
  MODERATOR
}

type Post {
  id: ID!
  title: String!
  content: String!
  author: User!
  comments: [Comment!]!
  publishedAt: DateTime
  createdAt: DateTime!
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

Best Practices

✅ DO

• Use clear, descriptive field names
• Design schemas around client needs
• Implement proper error handling
• Use input types for mutations
• Add subscriptions for real-time data
• Cache resolvers efficiently
• Validate input data
• Use federation for scalability

❌ DON'T

• Over-nest queries deeply
• Expose internal database IDs
• Return sensitive data without authorization
• Create overly complex schemas
• Forget to handle null values
• Ignore N+1 query problems
• Skip error messages