Introduction to GraphQL

Learn about GraphQL, how it works, and how to use it.

Transcript

1. Introduction to GraphQL
   

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2. GET https://2017.es.pycon.org/speakers/me
   {
   "name": "Adrián Matellanes",
   "roles": [
   "Lead API Developer",
   "Málaga Python Organizer"
   ],
   "worksAt": "Ebury",
   "twitter": "@_amatellanes",
   "github": "github.com/amatellanes"
   }
   

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3. What’s GraphQL?
   

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4. A programming language
   

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5. A special type of database
   

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6. A library
   

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7. A Query Language for APIs
   

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8. Why GraphQL?
   

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9. Due to the nature of REST
   

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10. REST Problems
    

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11. GET /characters/1
    { "name": "Jon Snow" }
    

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12. "url": "http://anapioficeandfire.com/api/characters/583",
    "name": "Jon Snow",
    "culture": "Northmen",
    "born": "In 283 AC",
    "titles": [
    "Lord Commander of the Night's Watch"
    ],
    "aliases": [
    "Lord Snow",
    "Ned Stark's Bastard",
    "The Snow of Winterfell",
    "The Bastard of Winterfell",
    "Lord Crow"
    ],
    "allegiances": [
    "http://anapioficeandfire.com/api/houses/362"
    ],
    "books": [
    "http://anapioficeandfire.com/api/books/5"
    ],
    "povBooks": [
    "http://anapioficeandfire.com/api/books/1",
    "http://anapioficeandfire.com/api/books/2",
    "http://anapioficeandfire.com/api/books/3",
    "http://anapioficeandfire.com/api/books/8"
    

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13. Round Trip and Repeat Trip Times
    

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15. /episodes/1
    

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16. /episodes/1
    /characters/345
    /characters/563
    /characters/802
    /characters/441
    /characters/674
    

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17. /episodes/1
    /characters/345
    /characters/563
    /characters/802
    /characters/441
    /characters/674
    /reviews/3512
    

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18. Over/Under Fetching
    

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19. /episodes/1?fields=characters(name,playedBy)
    

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20. /episode_with_all_stuff
    /episode_with_amazing_pictures
    /episode_with_stuff_i_need_today
    /episode_with_stuff_for_mobile_app
    /episode_with_actors_and_reviews_and_images
    /episode_with_stuff_for_mobile_app_v2
    /episode_with_actors_and_reviews_but_no_images
    

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21. /episode_with_all_stuff
    /episode_with_amazing_pictures
    /episode_with_stuff_i_need_today
    /episode_with_stuff_for_mobile_app
    /episode_with_stuff_for_mobile_app_v2
    /episode_with_actors_and_reviews_and_images
    /episode_with_actors_and_reviews_but_no_images
    

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23. https://code.facebook.com/projects/
    

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24. Created July 1, 2015
    Updated September 20, 2017
    381 Forks
    6,078 Stars
    302 Commits
    82 Open Issues
    https://github.com/facebook/graphql
    

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26. “You will receive what you ask for no more, no less.”
    - Mark Allen
    

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38. GraphQL vs. REST
    

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39. REST Model
    

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40. Client
    /books /characters /houses
    Databases Services External APIs
    

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41. GraphQL Model
    

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42. Client
    Databases Services External APIs
    /graphql/
    

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43. Anatomy of a GraphQL
    

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44. {
    me {
    name
    }
    }
    

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45. {
    me {
    name
    }
    }
    {
    "me": {
    "name": "Jon Snow"
    }
    }
    

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46. Scalar types
    

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47. Int
    Float
    String
    Boolean
    ID
    Date
    enum
    

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48. GraphQL Schema Definition Language
    

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49. type Query {
    allCharacters: [Character]!
    character(id: ID!): Character
    }
    

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50. type Query {
    allCharacters: [Character]!
    character(id: ID!): Character
    }
    Root Type
    

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51. type Query {
    allCharacters: [Character]!
    character(id: ID!): Character
    }
    Root Fields
    

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52. type Query {
    allCharacters: [Character]!
    character(id: ID!): Character
    }
    Arguments
    

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53. type Query {
    allCharacters: [Character]!
    character(id: ID!): Character
    }
    Return Types
    

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54. type Character {
    name: String!
    house: House!
    }
    type House {
    name: String!
    words: String!
    members: [Character]!
    }
    

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55. type Character {
    name: String!
    house: House!
    }
    type House {
    name: String!
    words: String!
    members: [Character]!
    }
    Object Type
    

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56. type Character {
    name: String!
    house: House!
    }
    type House {
    name: String!
    words: String!
    members: [Character]!
    }
    Fields
    

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57. type Character {
    name: String!
    house: House!
    }
    type House {
    name: String!
    words: String!
    members: [Character]!
    }
    Return Types
    

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58. Queries for fetching data
    from the server
    

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59. query CharactersNameAndHouse {
    allCharacters {
    name
    house {
    words
    }
    }
    }
    

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60. query CharactersNameAndHouse {
    allCharacters {
    name
    house {
    words
    }
    }
    }
    Operation Type
    

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61. query CharactersNameAndHouse {
    allCharacters {
    name
    house {
    words
    }
    }
    }
    Operation Name
    

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62. query CharactersNameAndHouse {
    allCharacters {
    name
    house {
    words
    }
    }
    }
    Selection Set
    

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63. query CharactersNameAndHouse {
    allCharacters {
    name
    house {
    words
    }
    }
    }
    Fields
    

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64. query CharactersNameAndHouse {
    allCharacters {
    name
    house {
    words
    }
    }
    }
    {
    "data": {
    "allCharacters": [
    {
    "name": "Daenerys Targaryen",
    "house": {
    "words": "Fire and Blood"
    }
    },
    {
    "name": "Jon Snow",
    "house": {
    "words": "Winter Is Coming"
    }
    }
    ]
    }
    }
    

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65. query {
    character(name: "Hodor") {
    name
    house {
    words
    }
    }
    }
    Arguments
    

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66. query CharacterByName($name: String!) {
    character(name: $name) {
    name
    }
    }
    {
    "name": "Hodor"
    }
    Variables
    

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67. query {
    character(name: "Hodor") {
    ...CharacterFragment
    }
    }
    fragment CharacterFragment on Character {
    name
    house {
    words
    }
    }
    Fragments
    

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68. {
    character(name: "Hodor") {
    ... on Character {
    name
    house {
    words
    }
    }
    }
    }
    Inline Fragments
    

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69. Mutations for manipulating data
    and fetch the updated result
    

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70. type Mutation {
    createCharacter(name: String!): Character
    }
    

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71. mutation CharacterMutation {
    createCharacter(name: "Sansa Stark") {
    name
    }
    }
    {
    "data": {
    "createCharacter": {
    "name": "Sansa Stark"
    }
    }
    }
    

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72. Subscriptions for real-time updates
    

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73. type Subscription {
    newCharacter: Character!
    }
    

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74. subscription NewCharacterSubscription {
    newCharacter {
    name
    }
    }
    {
    "data": {
    "newCharacter": {
    "name": "Tyrion Lannister"
    }
    }
    }
    

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75. Query Execution
    

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76. {
    getHouse(id: 5) {
    name
    words
    members {
    name
    }
    }
    }
    

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77. name words members
    getHouse(id: 5)
    { name, words, members }
    [ { name }, { name } ]
    name name
    

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78. QUERY
    name words members
    getHouse(id: 5)
    { name, words, members }
    [ { name }, { name } ]
    name name
    

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79. QUERY getHouse(id: 5)
    { name, words, members }
    HOUSE name words members
    [ { name }, { name } ]
    name name
    

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80. QUERY getHouse(id: 5)
    { name, words, members }
    HOUSE name words members
    [ { name }, { name } ]
    CHARACTER name name
    

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81. Clients with Super Powers
    

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82. Introspection Queries
    

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83. {
    "data": {
    "__type": {
    "name": "Book",
    "kind": "OBJECT",
    "fields": [
    {
    "name": "title",
    "type": {
    "name": "String"
    }
    }
    ]
    }
    }
    }
    {
    __type(name: "Book") {
    name
    kind
    fields {
    name
    type {
    name
    }
    }
    }
    }
    

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85. GraphiQL
    

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87. Graphene
    GraphQL framework for Python
    

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88. Created September 24, 2015
    Updated September 20, 2017
    229 Forks
    2,356 Stars
    1,219 Commits
    87 Open Issues
    https://github.com/graphql-python/graphene
    

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91. "It’s important to understand that it isn’t all or nothing.
    GraphQL is in our future, but it isn’t our exclusive
    future."
    

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92. Thank you!
    

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