Gain insights into GraphQL's architecture and methodology. Learn about setting up servers, performing complex queries, and updating data with mutations using Apollo Server and Node.js. Discover practical deployment.

getting started with Node js and graph ql 2-01.png

node.tar.gz

nodeapollospa

GraphQL is a query language for web APIs and a runtime for fulfilling queries with existing data. GraphQL gives clients the power to ask for precisely what they need, making it easy to evolve APIs with powerful developer tools.

This course is an introduction to GraphQL using the Node.js JavaScript runtime environment and Apollo Server. You’ll start with an introduction to GraphQL’s architecture and functions before exploring the structure of GraphQL data and learning to perform meaningful, complex queries. You’ll then learn how to update server data using mutations. Next, you’ll explore the GraphQL type system and schemas to set up a GraphQL server using Apollo Server. Once the server is set up, you’ll implement a full GraphQL application using Apollo and Node.js.

By the end of this course, you’ll have a rich understanding of GraphQL’s architecture and methodology and be prepared to deploy GraphQL applications to the web using Apollo and Node.js.

Getting Started with GraphQL using Node.js

In this lesson, we'll learn how a GraphQL query is executed by a GraphQL server that returns a response that reflects the structure of the invoked GraphQL query.

The sample query below is the same as the type system used throughout the lesson.

    type Pizza {
      id: Int!
      pizza: String!
      stock: Int!
      toppings: [Topping!]!
    }

    type Topping {
      id: Int!
      topping: String!
    }

    type Query {
      pizzas: [Pizza]
    }

Let’s use one of our previous queries as an example.


query{
  pizzas {
   __typename
    ... on Pizza {
      id
      toppings {
        id
        topping
      }
      pizza
    }
  }
}

We can conceptualize each field in a GraphQL query as a function.  Each field is mapped to a resolver function, which the GraphQL server developer provides. When a field is invoked, the corresponding resolver is called to generate the invoked value.

If a field generates a scalar value like a number or string, then the request is finished. However, if a field generates an object value, the query will also contain another field selection that applies to that object. The GraphQL resolver will continue until scalar values are generated. GraphQL queries are always resolved at a scalar value.

Learn how root fields and resolvers work in GraphQL. 

Root Fields and Resolvers

Learn how root fields and resolvers work in GraphQL.

Introduction

Getting to Know GraphQL

Queries

Mutations

Schemas and Types

Schema Validation

Schema Execution

Schema Introspection

GraphQL Best Practices

GraphQL Exam

Root Fields and Resolvers