Want to get up and running with building and consuming GraphQL APIs? In this course, Building Scalable APIs with GraphQL, you'll learn what separates GraphQL from other languages and API runtimes, like REST APIs, as well as what problems GraphQL solves, and how to use it for declarative data communication. In this project we are working with create-react-app, and if you haven't used TypeScript in a CRA project before, you're in luck, as it's quite easy to set up. This is all necessary setup for the final piece in this series, where I'll show you how to combine all this knowledge together to create a schema for our example application — a document management system. In component, we need to pass the mutations and variables as a prop and use the vue scoped slot feature to pass down the results. [variables]: Is an optional object of variables that is required when query accepts some variables. I see them using blocks to define their mutations. You can use any technology for implementing GraphiQL server. In this course, learn how to get started with GraphQL. The need might be quite insidious when building less complex APIs, however, as with all applications, increasing the API capabilities increases complexity in some way and therefore requires a newer approach to handling this complexity without causing pain to the consumers of our API - even when it's only us. He specializes in Laravel and Ember development. r/graphql: A place for interesting and informative GraphQL content and discussions. The query and response work just as the previous mutation. One particular type of mutation is operations that change users, like signing up a new user. It should contain a single GraphQL query operation that will be executed once the mutation has completed. The exception is an introspection query, which is a simple GET to the endpoint. Need to have single HTTP endpoint for managing CRUD operation and performing custom actions. These are the equivalent to the POST, PUT, PATCH and DELETE in HTTP/REST speak. environment), instead of referencing a global environment. config: mutation: The graphql tagged mutation query. Query variables. In this post I will show how we can create a middleware to validate the input arguments of any GraphQL Mutation using Yup. Mopheus GraphQL can also convert your GraphQL Schema or Query to Haskell types and validate them in compile time. Implementing GraphQL modifiers. They include creating, updating, and deleting Content items. js, Express, amd a library called express-graphql to make it possible; querying, we will cover different ways of querying our server like normal queries, paramterized queries and also how to change data with mutations # Why GraphQL. GraphQL has been on a hype recently; to be fair, it's worth it. Virtual Cookie Policy - To give you the best possible experience, this site uses cookies. subscription, which is the name of our graphql tag variables (if any) In the children section, we can render some specific component or information based on the response of the subscription, or simply return null. Linux installation. Vue apollo package also provides us component which is used to send the mutations to the graphql API. Schema Schema // A GraphQL language formatted string representing the requested operation. Rules and recommendations mentioned here were the results of 3 years' experience of using GraphQL both on the frontend and backend sides. GraphQL is a new and innovative way to query and mutate graphs of data according to the needs of the GraphQL consumer. • Master GraphQL in React applications in great depth with Apollo Boost, Apollo Client, and Apollo Client State About This course is for developers keen to build complete, full-stack applications with cutting-edge React user interfaces, powered by a robust Python backend and using GraphQL on the server and client. The syntax is client. This is all necessary setup for the final piece in this series, where I'll show you how to combine. We can compare mutations in GraphQL to CUD(Create, Update, Delete) operation that we see a lot in the APIs world. A unique identifier for the client performing the mutation. Once installed, execute the following commands to get your Prisma API up-and-running and start sending queries and mutations to it: prisma init hello-world # Select a *Demo server* from the interactive prompt cd hello-world prisma deploy prisma playground You can now start sending queries and mutations to your Prisma API. It relies on a GraphQL server exposing connections in a standardized way. GraphQL - Validation - While adding or modifying data, it is important to validate the user input. From the new window or tab, let's send the setLiftStatus mutation:. Be sure to use the correct variable name as the JSON key:. This is an example API, showing how to create a GraphQL endpoint in Node. Over at localhost:4000 we should have GraphQL Playground up and running with a query for user { name } returning our empty array. If your query string contains variables, you can provide values in a hash of { String => value } pairs. The headless CMS developers love. Using variables, you can shape the results of a query. To learn more about the basics of GraphQL, how it differs from REST, its building blocks like schema, resolvers, queries, and mutations, please refer to the previous post Creating a GraphQL Server with Nodejs. Landing Page Current status Components for fast loading. The graphql function is going to handle all the API requests, and the playground endpoint will create an instance of GraphQL Playground for us, which is a great way to try out our GraphQL API in a web browser:. Together, these form a single GraphQL framework called GRANDstack. The mutation is used to update data on a GraphQL server and subscription is used to listen for any event on the server. By default, it will just try the name you are using for the data in the component (which is the key in the apollo object), in this case world. graphql files. Responses to requests are returned in this playground-like environment. Building Northwind’s GraphQL. In GraphQL, editing data is done via a Mutation. And greatly improves the performance. GraphQL is gaining traction as one of the most popular ways to create an API. Execute queries and mutations in the GraphQL IDE and explore the functionality of it. In the query section, GraphQL variables begin with the $ symbol and are declared after the query or mutation keyword, similar to passing an argument to a function. We are going to use graphQL file in client, so we need to define a loader here. Step 4 Paste the following mutation into the left pane of the app Playground and hit the Play -button (or use the keyboard shortcut CMD+Enter ):. Whether that would be a POST PATCH PUT or DELETE in a REST API, is anyone. GraphQL List, how to use arrays in your GraphQL schema. From the point of view of the code, there is no reason that a Query can't change data on the server. 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. A much richer tool to play with your queries is GraphQL Playground. Be sure to use the correct variable name as the JSON key:. This article will explain how to create and execute GraphQL queries within Insomnia. To follow along step-by-step, check out the blog post. 0 (including alpha versions) should be good!. Notice also that instead of taking a component as argument and returning a component, the function now takes an options object, and returns a function that returns a component, which is then itself applied to the component being wrapped. Once a GraphQL service is running (typically at a URL on a web service), it can be sent GraphQL queries to validate and execute. The big difference is unlike with queries were things broke if I didn’t start the string with the word “query”, mutations need to not have that. All calls are validated and executed against the schema. Day 1: GraphQL Kickoff GraphQL Query Language. The industry is still divided, though. The mutate function optionally takes variables, optimisticResponse, refetchQueries, and update; however, you can also pass in those values as props to the Mutation component. In our case, we are defining the object to be inserted as a mutation. org left it to other people to design a way to handle the process. Actually no fun yet, we can only execute queries without getting any result. Open Sans and Source Code Pro fonts; Rendering the component; The GraphQL Playground requires React 16. Visit the Playground. for example when implementing a GraphQL Server, there are 2 options for you:. In order to keep the articles short and concise, we will do the preparation work in this post. I wish we would provide GraphQL the EF DbContext and it would solve everything. It focuses on simple apps and execution using React hooks for building queries and mutations. Schema Schema // A GraphQL language formatted string representing the requested operation. Any GraphQL query can be parametrized by defining variables. Some of these options are described in more detail below, see GraphQL::Query#initialize for more information. A user is just a string, which represents its name. Change data using Mutations. createFolder and updateFolder. Eu] [UDEMY] Full-Stack Vue with GraphQL - The Ultimate Guide - [FTU] could be available for direct download. GraphQL is a specification that defines a type system, query language, and schema language for your Web API, and an execution algorithm for how a GraphQL service (or engine) should validate and execute queries against the GraphQL schema. We use cookies for various purposes including analytics. We also include the recommendations and experience of Caleb Meredith (PostGraphQL author, Facebook ex-employee) and Shopify engineers. GraphQL - Validation - While adding or modifying data, it is important to validate the user input. While some venture to say it. yml file we define two functions, graphql and playground. To follow along with these queries, go to the Pet Library GraphQL Playground. fixture: This is optional and it is if you want to pass your custom fixtures. An example is when we are interested in querying user data with a particular ID. In order to explore the GraphQL API, you can use an interactive GraphiQL environment which is available as a part of Impex. In this lesson, we will send mutations to register new users. The updateFactSheet mutation changes an existing Fact Sheet by following the "JSON Patch" logic described in RFC 6902. We decided to not invest time into moving to another service because more full-featured Apollo Server playgrounds currently exist. Mutations are executed serially. OK, I Understand. Execute a GraphQL query on the schema. Welcome to the Cosmic JS GraphQL documentation. Learn about all of the features and methods to perform queries and mutations on your Bucket content. This time, I'll be focusing on queries, mutations and subscriptions. This mutation will allow you to post new links to the server. Variable structure. GraphQL also has the ability to update the data stored on the server, by means of mutations. Custom mutations enable you to write exactly the business logic you need with access to all of your data all wrapped up in a PostgreSQL function. In our case, we are defining the object to be inserted as a mutation. NET Schema, Types, Query. The CLI reads the secret from the PRISMA_MANAGEMENT_API_SECRET environment variable and uses it to generate the JWT which it then attaches to the API request. In this post, we give you insight into GraphQL features covering queries, mutations, and subscriptions. Based on your current implementation, extend the GraphQL API with full CRUD functionality for the Link type. While GraphQL's syntax looks clean and simple at first glance, it's easy to see how quickly simple queries evolve into complex behemoths. the query object type). These can be both simple scalar values as well as objects. This struct can then be passed to the post_graphql_mutation helper, that will post the request with the correct params, like a GraphQL client would do. Source code for Apollo Angular Boost GraphQL Tutorial on Github. In the previous articles basic GraphQL setup in express and input object type as an argument for GraphQL mutations, we used GraphiQL for executing queries and mutations. You have to explicitely allow procedures to be exposed, via the config setting graphql. In addition to adding query arguments directly to queries, GraphQL allows to pass in "query variables". But if you manipulate queries at runtime, you can’t take advantage of tooling that could quickly detect compatibility issues between client and server. Implementing GraphQL modifiers. So let’s start with the first thing, our mutation query: We will be using the gql helper from the graphql-tag library to create. GraphQL provides query variables as a way to parameterize query strings. In the Configure method, we tell ASP. com is now LinkedIn Learning! To access Lynda. Figure 6: The mutation, addMovie is declared to return the fields, id and title upon success. In GraphQL you can assign Default values to the. Finally, in the serverless. The best way to learn GraphQL for. It is a direct proxy for request from graphql-request , a library that enables a low level request pattern for GraphQL servers using fetch. Use the graphql_sync function from graphql-core to provide the result for a query string. For our javascript signUp method, we will use a Mutation that is almost the same as the one we used on the GraphQL Playground, but while there we used hardcoded values, here we must set variables to assume values that the user types on the forms. The content of the query object is a string that. Implementing GraphQL modifiers. Some of these options are described in more detail below, see GraphQL::Query#initialize for more information. In order to keep the articles short and concise, we will do the preparation work in this post. This is an example of GraphQL server supporting Relay written with Play framework and Sangria, it also uses webpack for client side asset generation. Cookie Policy - To give you the best possible experience, this site uses cookies. environment), instead of referencing a global environment. GraphQL Support. [FreeTutorials. Introduction. Each plays a key role in the build process. Shopify Discussion. perform(mutation: Mutation() {(result, error)}) where comes from the GraphQL statements that amplify codegen types created. AWS AppSync AWS AppSync Developer Guide Launch a Sample Schema Quick Start This section describes how to use the AWS AppSync console to do the following: • Launch a sample event app schema • Automatically provision a DynamoDB data source and connect resolvers • Write GraphQL queries and mutations • Use the API in the sample app. Basic GraphQL queries in GDC. We simply have an empty system. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. One of our concerns was potential performance hits on the server side after utilizing graphql-ruby. Christopher Moore is a full-stack PHP developer with over seven years of experience. Welcome to the second half of the Angular Firebase GraphQL tutorial. Queries: reading data. If an array of objects with this shape is specified then Apollo Client will refetch these queries with their variables. GraphQL Playground with Gatsby. Using mutations. Default values are supported. In this lesson, we will send mutations to register new users. One particular type of mutation is operations that change users, like signing up a new user. GraphQL Conf is organized by Prisma and Honeypot. GraphQL provides query variables as a way to parameterize query strings. How to use? At first, you need to pass complexity as an option to the decorator on a field/query/mutation. The variables key can be optional depending on the request. In order to keep the articles short and concise, we will do the preparation work in this post. The final piece of the GraphQL puzzle is mutations. Vue apollo package also provides us component which is used to send the mutations to the graphql API. This section introduces the GraphQL mutation. Provides a tabbed interface for editing and testing GraphQL queries/mutations with GraphiQL. A user is just a string, which represents its name. This post will cover some options for GraphQL clients. In either case, the operation is a simple string that a GraphQL server can parse and respond to with data in a specific format. I wish we would provide GraphQL the EF DbContext and it would solve everything. They are executed almost identically. GraphQL Playground with Gatsby. Compatibility with GraphQL. One particular type of mutation is operations that change users, like signing up a new user. Finally, add authentication to lock down resources. These are the equivalent to the POST, PUT, PATCH and DELETE in HTTP/REST speak. js without having to go through HTTP you can use some other exported functions that PostGraphile provides. For example, we may need to ensure that the value of a field is always not null. It might help to take a closer look at their documentation. In the above case, it is optional. PlayerRepository is a simple Entity Framework Core-based repository class defined in the solution's data layer and injected into NHLStatsQuery by the service container we saw earlier. And that’s how we get GraphQL Playground to work with Gatsby! So that’s how we get from GraphQL’s default GraphiQL IDE to GraphQL Playground. We can get data in GraphQL with queries, and to create, modify or delete data we can use mutations. js, Graphql and MongoDB CRUD Web Application by Didin J. For example, if the mutation defines an $input variable, this object should contain an input key, whose shape must match the shape of the data expected by the mutation as defined by the GraphQL schema. From the new window or tab, let's send the setLiftStatus mutation:. GraphQL variables allow you to re-use the same queries/mutations with different arguments. Designing GraphQL Mutations for Creating, Changing, or Deleting MongoDB Documents Now that we can query for documents, we probably want a way to create documents. RequestString string // The value provided as the first argument to resolver functions on the top // level type (e. The Client class used to create and send GraphQL documents, fragments, queries and mutations. Here is an example of a mutation operation:. When we specified the return type of the mutations we did it so we can query their result. Jump to example. Using composer, run: composer require webonyx/graphql-php Upgrading. -alpha-868 GraphiQL PM> Install-Package graphiql $ dotnet add package graphiql. The mutations are protected behind authentication provided by Okta. The value for query should be a single string consisting of a correctly formatted GraphQL query or mutation. GraphQL Playground with Gatsby. GraphQL also has the ability to update the data stored on the server, by means of mutations. GraphQL mutations create and modify objects, similar to a PUT, POST, or DELETE request in REST. Interactive GraphQL console. これでgraphcoolという名前のディレクトリが作成されて、準備完了です。簡単! vueの用意 次にvueの環境を用意していきます。 後々使うものも入れてしまいます。 npm install --save vue-apollo apollo. In GraphQL, editing data is done via a Mutation. The graphql specification says that mutations MUST be executed serially and in the order in which the query fields occur. Finally, add authentication to lock down resources. All you need to do is define your complexity cost for the fields (fields, mutations, subscriptions) inTypeGraphQL and implement graphql-query-complexity in whatever GraphQL server you have. Postman now supports GraphQL! With the newest update, Postman can send GraphQL queries in the request body, use GraphQL variables, autocomplete queries, and create/store GraphQL schemas directly in Postman. GraphQL Playground provides a React component responsible for rendering the UI and Session management. Variables can be used in the query string and the values of those variables can be sent in a separate. GraphQL List, how to use arrays in your GraphQL schema. The schema contains two mutations per Content type, e. Let's look at an example of 2 requests to our GraphQL server from our Apollo GraphQL playground — which comes with Apollo Server straight out of the box. building a server, we will use Node. GraphQL is a new and innovative way to query and mutate graphs of data according to the needs of the GraphQL consumer. The above doesn’t sound like much and it isn’t. for example when implementing a GraphQL Server, there are 2 options for you:. yml file we define two functions, graphql and playground. Input object types must map to server defined objects. NET framework to build a fully functional GraphQL endpoint. saveFixture: By default is false , if you pass fixtures, and set it to true when you make the same query again, it will return the fixture value. In this course, learn how to get started with GraphQL. Welcome - [Instructor] The GitHub GraphQL API has a ton of different mutations that we can take advantage of. Like we covered earlier, the decision of whether or not to make the switch at all comes down to whether the additional features offered in GraphQL Playground are. In our case, we are defining the object to be inserted as a mutation. Rather than getting the data from the back-end, we are returning some hard-coded books in our. Prerequisites: Node. In GraphQL, this is done using so-called mutations. js that can query and mutate data from a MongoDB database that is running on Ubuntu 18. While you have POST, GET, PUT, and others as request methods in a REST API, for GraphQL, you have just Query (equivalent of GET in REST) and Mutation (equivalent of PUT, POST, PATCH and DELETE in REST). This is where variables come in. In my opinion, a mutation is a special query, that lets everyone know we are modifying data on the server. Now that you have a solid grasp on making a query, let’s focus on mutations. 🚀 Integrate GraphQL in your Vue. Execute a GraphQL query on the schema. Welcome - [Instructor] The GitHub GraphQL API has a ton of different mutations that we can take advantage of. js stack using JavaScript and GraphQL. NET Core pipeline that we use GraphQL with the Northwind schema along with GraphQL playground - it’s an interactive UI to test the implementation for GraphQL. Mutations make modifications to data and return a result. API Development in. Follow the instructions to get started quickly, pick a tutorial to setup a Prisma service with your preferred database or use a bootstrap an entire GraphQL server based on Prisma and Prisma bindings. Lecture and exercises: The terminologies and design principles of GraphQL, the GraphQL way of creating APIs for hierarchical data, how GraphQL is product-centric with client-specified queries, how GraphQL plays well with existing code, and how to work with the GraphQL editor. #Cosmic JS GraphQL API. 有了前面的基礎,相信學習 Mutation 也是輕鬆就上手!不過這幾天一下子吸收了這麼大量的知識,可能已經開始吃不消了,所以明天我們就來依靠現有的技術來打造一個實用的 GraphQL API 吧!. development file. Compatibility with GraphQL. In its essence, there are two ways to talk to a GraphQL API using HTTP: Using GET or POST requests. js, Express, amd a library called express-graphql to make it possible; querying, we will cover different ways of querying our server like normal queries, paramterized queries and also how to change data with mutations # Why GraphQL. variables: Object. Then when we call the actual mutation on line 2 in the top left box we pass them as variables which will automatically map them. Press J to jump to the feed. When we specified the return type of the mutations we did it so we can query their result. GraphQL Playground provides a React component responsible for rendering the UI and Session management. You can find the source code of this demo for this GitHub repository. yml file we define two functions, graphql and playground. Like we covered earlier, the decision of whether or not to make the switch at all comes down to whether the additional features offered in GraphQL Playground are. The right panel highlighted with a red border, in the GraphQL Playground screenshot in Figure 7 below shows that a message was emitted out of the API upon a movie. To perform a mutation you need to have a root Mutation object that is an ObjectGraphType. The downside of this is that, when Types::Post is queried in other contexts, the same authorization check may not be applied. From the point of view of the code, there is no reason that a Query can't change data on the server. It defines the mutation operation, consisting of the name of the mutation and the fields I want as part of the response (just like a query). These are the equivalent to the POST, PUT, PATCH and DELETE in HTTP/REST speak. The Road to Variables. @MarkLechtermann Mark Lechtermann @MarkLechtermann GraphQL with. In the query section, GraphQL variables begin with the $ symbol and are declared after the query or mutation keyword, similar to passing an argument to a function. The keys should not contain "$". We just need to declare what options we want, add any arguments (if any), and declare what type should be returned when completed. GraphQL file uploading seems like it was an after thought. These are the variables of your query. And that's how we get GraphQL Playground to work with Gatsby! So that's how we get from GraphQL's default GraphiQL IDE to GraphQL Playground. GraphQL is gaining traction as one of the most popular ways to create an API. GraphQL Support. You declare a name for the variables you will use by using a $. [variables]: Is an optional object of variables that is required when query accepts some variables. Create a GraphQL HTTP server with Express. The graphql specification says that mutations MUST be executed serially and in the order in which the query fields occur. request allows you to send a GraphQL query / mutation to the GraphQL API abstracted by this binding. Getting Started. Orange Box Ceo 6,531,520 views. An example is when we are interested in querying user data with a particular ID. And that’s how we get GraphQL Playground to work with Gatsby! So that’s how we get from GraphQL’s default GraphiQL IDE to GraphQL Playground. It should contain a single GraphQL query operation that will be executed once the mutation has completed. Because GraphQL is statically typed, it can actually validate for you that you are passing in the right variables. How to manage file uploads in GraphQL mutations using Apollo/Graphene was originally published in freeCodeCamp on Medium, where people are continuing the conversation by highlighting and responding to this story. You will learn more about the syntax for these variable definitions in our next article about the schema language GraphQL. Custom scalars and enums. Draqula is a lightweight GraphQL client, perfect for smaller and simpler React apps. -alpha-868 GraphiQL PM> Install-Package graphiql $ dotnet add package graphiql. Note: This guide does not cover GDC GraphQL mutation operations. In addition, it comes out-of-the-box in Apollo Server 2. Join Glenn Block for an in-depth discussion in this video Create a mutation and verify the change, part of API Development in. You can open a new tab to add the mutation. Introduction. These can be both simple scalar values as well as objects. This time, I'll be focusing on queries, mutations and subscriptions. This is where we send the input data as a JSON object. GraphQL Playground running on post 4000 That's it!. Even though GraphQL has gained a lot of popularity over the past year, building the backend for a GraphQL API can be a major pain and a source of confusion for developers new to the ecosystem. These are the equivalent to the POST, PUT, PATCH and DELETE in HTTP/REST speak. There’s a single query, books, that returns a list of Books. Then when we call the actual mutation on line 2 in the top left box we pass them as variables which will automatically map them. The API is fully CRUD capable, allowing you to perform Create, Read, Update, and Delete requests to your Cosmic JS Buckets. GraphQL Query Language. The request body should be JSON-formatted, with two keys: query and variables. GraphQL provides query variables as a way to parameterize query strings. Why we Use GraphQL Using GraphiQL and GraphQL Playground Building Queries Changing Data with Mutations Using Arguments and Variables Listening for Changes with Subscriptions Reviewing a Schema with Introspection Designing GraphQL Schemas. nxplorerjs-microservice-starter Cloud Native Node JS Express Reactive Microservice Starter Template (REST/GraphQL) This project provides complete Node JS / Typescript based microservices template with all that will be needed features for production deployment , monitoring , debugging , logging , security , CI/CD. GraphQL is a strongly typed query language, and Typescript is a typed superset of JavaScript - together they are a match made in heaven! In this tutorial, I will teach you how to create a GraphQL API and use Node. You can resolve these operations using your regular cloud code functions. In GraphiQL or GraphQL Playground, there is a window for Query Variables in the lower left corner. the "Queries and Mutations" section of the. Additionally, since the authorization code is coupled with the GraphQL API, the only way to test it is via GraphQL queries, which adds some complexity to tests. It defines the mutation operation, consisting of the name of the mutation and the fields I want as part of the response (just like a query). We pass variables separately from the query document and also reduce the code significantly. This command will start a local graphql-playground server which is connected to your AppSync endpoint. The syntax for our mutations is almost the same as for our query. graphql files. It complements the GraphQL query because it is used for writing data instead of reading it. js, Express, amd a library called express-graphql to make it possible; querying, we will cover different ways of querying our server like normal queries, paramterized queries and also how to change data with mutations # Why GraphQL. Introduction to GraphQL (55 minutes). If your query string contains variables, you can provide values in a hash of { String => value } pairs. GraphQL was designed to solve one of the biggest drawbacks of REST-like APIs. Press question mark to learn the rest of the keyboard shortcuts. right? Local server port is on at 4000 and local prisma port is on 4466. com courses again, please join LinkedIn Learning. r/graphql: A place for interesting and informative GraphQL content and discussions. yml file we define two functions, graphql and playground. AWS AppSync AWS AppSync Developer Guide Launch a Sample Schema Quick Start This section describes how to use the AWS AppSync console to do the following: • Launch a sample event app schema • Automatically provision a DynamoDB data source and connect resolvers • Write GraphQL queries and mutations • Use the API in the sample app. The big difference is unlike with queries were things broke if I didn’t start the string with the word “query”, mutations need to not have that. Lecture and exercises: The terminologies and design principles of GraphQL, the GraphQL way of creating APIs for hierarchical data, how GraphQL is product-centric with client-specified queries, how GraphQL plays well with existing code, and how to work with the GraphQL editor. js file and add an environment variable file, typically called. Comparing GraphQL to REST, queries operate like GET requests, while mutations operate like POST/PATCH/DELETE. I hope you’ve had fun learning about GraphQL and experimenting with the Playground. GraphQL isn't tied to any specific database or storage engine and is instead backed by your existing code and data. A GraphQL query can be parameterized with variables, maximizing query reuse, and avoiding costly string building in clients at runtime. Actually no fun yet, we can only execute queries without getting any result. Use interfaces and unions. Execute a GraphQL query on the schema. Figure 6 below shows the actual mutation for addMovie executed in GraphQL Playground. While GraphQL queries perform read operations, mutations change the data.