GraphQL Queries and Mutations

• GraphQL Queries
  • Standard Query
  • Aliases
  • Fragments
  • Variables
  • Mutations
  • Mutations with Variables

GraphQL Queries

Standard Query

Use the standard query to get all Posts out of your database:

1. Query:

query{
  posts{
    title
    author{
      name
    }
  }
}

2. Response:

"data": {
  "posts": [
    {
      "title": "First Post",
      "author": {
        "name": "Author Name"
      }
    },
    {
      "title": "Second Post",
      "author": {
        "name": "Author Name"
      }
    },
    {
      "title": "Third Post",
      "author": {
        "name": "Author Name"
      }
    }
  ]
}

Aliases

Use aliases to query for multiple separate posts:

1. Query:

query{
  firstquery: post(id:2){
    title
    author{
      name
    }
  }
  secondquery: post(id:3){
    title
    author{
      name
    }
  }
}

2. Response:

"data": {
  "firstquery": {
    "title": "Second Post",
    "author": {
      "name": "Author Name"
    }
  },
  "secondquery": {
    "title": "Third Post",
    "author": {
      "name": "Author Name"
    }
  }
}

Fragments

Use fragments to shorten your queries:

1. Query:

query{
  firstquery: post(id:2){
    ...basicPostDetails
  }
  secondquery: post(id:3){
    ...basicPostDetails
  }
}

fragment basicPostDetails on Post{
    title
    author{
      name
    }
}

2. Response:

"data": {
  "firstquery": {
    "title": "Second Post",
    "author": {
      "name": "Author Name"
    }
  },
  "secondquery": {
    "title": "Third Post",
    "author": {
      "name": "Author Name"
    }
  }
}

Variables

Use fragments to shorten your queries - the query variable has to be send alongside, e.g. user clicked on post number two -> {"postID": 2}:

1. Query:

query($postId: Int!) {
  post(id:$postId){
    ...basicPostDetails
  }
}

fragment basicPostDetails on Post{
    title
    author{
      name
    }
}

2. Response:

{
  "data": {
    "post": {
        "title": "Second Post",
        "author": {
          "name": "Author Name"
        }
      }
    }
}

Mutations

Queries retrieve data from your database. A mutation can be used to make changes to your data - e.g. add a post:

1. Query:

mutation {
  addPost( post: {
    title: "New Post",
    content: "Post content",
    author: "sd35xzdfg"
  }){
    title,
    author: {
      name
    }
  }
}

2. Response:

{
  "data": {
    "post": {
        "title": "New Post",
        "author": {
          "name": "Author Name"
        }
      }
    }
}

Mutations with Variables

With a variable the new post data has to be passed along as a javascript object, e.g.:

{"post": {
    "title": "New Post",
    "content": "Post content",
    "author": "sd35xzdfg"
  }
}

1. Query:

mutation ($post: PostInput!) {
  addPost( post: $post){
    title,
    author: {
      name
    }
  }
}

2. Response:

{
  "data": {
    "post": {
        "title": "New Post",
        "author": {
          "name": "Author Name"
        }
      }
    }
}