| graphql |
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| #graphql |
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| Table of Contents |
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| About |
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| Chapter 1: Getting started with graphql |
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| Remarks |
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| When should I use GraphQL? |
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| Implementations |
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| Client Libraries |
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| Dev Tools |
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| Versions |
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| Examples |
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| Server Installation & Implementation |
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| GraphQL.js |
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| Example Server |
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| Server Middleware Alternatives |
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| GraphQL Query Language (GQL) |
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| Query for All Film Titles from Star Wars Schema |
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| Query for Planet Residents to Star Wars film "A New Hope" |
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| Schema Definition |
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| Schema Object Type |
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| Schema Query |
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| Query Nick's Friend's Friend's Friends |
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| Credits |
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| About |
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| You can share this PDF with anyone you feel could benefit from it, downloaded the latest version |
| from: graphql |
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| It is an unofficial and free graphql ebook created for educational purposes. All the content is |
| extracted from Stack Overflow Documentation, which is written by many hardworking individuals at |
| Stack Overflow. It is neither affiliated with Stack Overflow nor official graphql. |
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| The content is released under Creative Commons BY-SA, and the list of contributors to each |
| chapter are provided in the credits section at the end of this book. Images may be copyright of |
| their respective owners unless otherwise specified. All trademarks and registered trademarks are |
| the property of their respective company owners. |
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| Use the content presented in this book at your own risk; it is not guaranteed to be correct nor |
| accurate, please send your feedback and corrections to info@zzzprojects.com |
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| https://riptutorial.com/ |
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| 1 |
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| Chapter 1: Getting started with graphql |
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| Remarks |
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| GraphQL is a query language for APIs and a runtime for fulfilling those queries with |
| your existing data. GraphQL provides a complete and understandable description of |
| the data in your API, gives clients the power to ask for exactly what they need and |
| nothing more, makes it easier to evolve APIs over time, and enables powerful |
| developer tools. |
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| When should I use GraphQL? |
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| GraphQL is intended to be the outward facing HTTP API for any kind of application but it is most |
| powerful when the data is normalized with highly interconnected Collections|Tables|Nodes. The |
| GraphQL Query Language (GQL) is designed to project interconnected data in a very intuitive and |
| flexible way. |
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| Implementations |
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| GraphQL itself is a Spec and is implemented by a number of different programming languages. |
| These are the most popular supported languages |
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| GraphQL.js |
| graphql-ruby |
| Graphene (Python) |
| Sangria (Scala) |
| graphql-java |
| graphql-clj (Clojure) |
| graphql-go |
| graphql-php |
| graphql-dotnet (C# / .Net) |
| absinthe (Elixir) |
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| Client Libraries |
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| Running queries from the client side can be done with any HTTP client but client side libraries can |
| be very beneficial. |
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| Relay |
| Apollo |
| Lokka |
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| https://riptutorial.com/ |
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| 2 |
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| Dev Tools |
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| graphiql /ˈɡrafək(ə)l/ - An interactive in-browser GraphQL IDE. |
| libgraphqlparser - A GraphQL query language parser in C++ with C and C++ APIs. |
| GraphQL Language Service - An interface for building GraphQL language services for IDEs |
| (diagnostics, autocomplete etc). |
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| Versions |
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| Version Release Date |
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| v0.5.0 |
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| 2016-04-08 |
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| v0.6.0 |
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| 2016-05-10 |
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| v0.6.1 |
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| 2016-07-07 |
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| v0.6.2 |
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| 2016-07-21 |
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| v0.7.0 |
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| 2016-08-26 |
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| v0.7.1 |
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| 2016-09-29 |
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| v0.7.2 |
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| 2016-10-10 |
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| v0.8.0 |
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| 2016-11-10 |
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| v0.8.1 |
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| 2016-11-11 |
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| v0.8.2 |
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| 2016-11-16 |
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| Examples |
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| Server Installation & Implementation |
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| GraphQL.js |
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| GraphQL.js is a JavaScript reference implementation for GraphQL. You can install it via npm: |
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| Initialize npm in your project if you have not done so already: npm init |
| Install GraphQL.js from npm: npm install --save graphql |
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| Example Server |
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| var { graphql, buildSchema } = require('graphql'); |
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| https://riptutorial.com/ |
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| 3 |
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| // Construct a schema, using GraphQL schema language |
| var schema = buildSchema(` |
| type Query { |
| hello: String |
| } |
| `); |
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| // The root provides a resolver function for each API endpoint |
| var root = { |
| hello: () => { |
| return 'Hello world!'; |
| }, |
| }; |
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| // Run the GraphQL query '{ hello }' and print out the response |
| graphql(schema, '{ hello }', root).then((response) => { |
| console.log(response); |
| }); |
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| Server Middleware Alternatives |
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| Express GraphQL Middleware |
| Hapi GraphQL Middleware |
| Koa GraphQL Middleware |
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| GraphQL Query Language (GQL) |
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| Instead of defining URL endpoints for each data resource, in GraphQL you define a single |
| endpoint that accepts GraphQL queries. Unlike traditional database query languages, GraphQL |
| Query Language (GQL) is a projection of data returned by a root level query. The GraphQL |
| schema will define the data model and root level queries and mutations. GQL executes those |
| queries and defines what data to return. |
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| Query for All Film Titles from Star Wars Schema |
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| https://riptutorial.com/ |
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| 4 |
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| GraphiQL Query |
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| https://riptutorial.com/ |
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| 5 |
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| Query for Planet Residents to Star Wars film "A New Hope" |
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| https://riptutorial.com/ |
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| https://riptutorial.com/ |
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| 7 |
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| GraphiQL Query |
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| Notice how the root query film() takes in the id parameter of the film "A New Hope" and the |
| projection from GQL returns the title, planets connected to the film, and then resident names of the |
| planets. Check out the Star Wars GraphiQL site to experiment with querying in GraphQL. |
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| Schema Definition |
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| In GraphQL the Schema defines the root execution queries and mutations as well as the types for |
| your data. |
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| Schema Object Type |
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| The Person type has two fields, one is a standard Scalar type and the other represents a |
| relationship to a list of other Person types that are 'friends'. Linking other types is what makes |
| GraphQL so powerful. Now in GraphQL Query Language (GQL), the client can traverse the friends |
| graph without any additional code or advanced querying. |
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| type Person { |
| id: ID |
| name: String |
| friends: [Person] |
| } |
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| Schema Query |
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| The person query looks up a single person by it's id. This is the entry point to your data for clients |
| using GQL. |
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| type Query { |
| person(id: ID!): Person |
| } |
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| Query Nick's Friend's Friend's Friends |
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| Now that we have a Person type and a person root query we can look up a person and as many |
| degrees of separation we want of the person's friends network. |
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| query { |
| person(id: 'nick'){ |
| id |
| name |
| friends{ |
| id |
| name |
| friends{ |
| id |
| name |
| friends{ |
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| https://riptutorial.com/ |
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| 8 |
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| id |
| name |
| } |
| } |
| } |
| } |
| } |
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| Read Getting started with graphql online: https://riptutorial.com/graphql/topic/7649/getting-started- |
| with-graphql |
|
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| https://riptutorial.com/ |
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| 9 |
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| Credits |
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| S. |
| No |
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| 1 |
|
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| Chapters |
|
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| Contributors |
|
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| Getting started with |
| graphql |
|
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| Community, jengeb, Nikordaris |
|
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| https://riptutorial.com/ |
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| 10 |
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