GraphQL Education & Training

GraphQL is a query language for APIs and a runtime for executing those queries with your existing data. It allows clients to request only the data they need, making it more efficient than traditional REST APIs.

• **Schema**: Defines the structure of your GraphQL API.
• **Types**: Specify the kind of data you can query.
• **Queries**: Fetch data from the server.
• **Mutations**: Modify data on the server.
• **Resolvers**: Functions that resolve queries to actual data.

GraphQL uses a strong type system to define the capabilities of an API.

• **Scalar Types**: Such as Int, Float, String, Boolean, and ID.
• **Object Types**: Represent a specific data structure.
• **Interfaces**: Define a set of fields that multiple types can implement.
• **Union Types**: Allow a field to return different types.
• **Enums**: Define a set of valid values for a field.

Queries

To fetch data, you use queries. Here’s an example query:

{
  user(id: "1") {
    name
    email
  }
}
                

Mutations

To modify data, you use mutations. Here’s an example mutation:

mutation {
  createUser(input: { name: "John Doe", email: "john@example.com" }) {
    id
    name
  }
}
                

Here are some best practices to follow when working with GraphQL:

• Use descriptive names for queries and mutations.
• Implement pagination for large datasets.
• Utilize fragments to avoid repeating fields.
• Version your API carefully.
• Use tools like GraphQL Playground for testing queries.